4H-imidazo[1,2-a]imidazoles for electronic applications

ABSTRACT

The present invention relates to compounds of formula 
                         
a process for their production and their use in electronic devices, especially electroluminescent devices. When used as host material for phosphorescent emitters in electroluminescent devices, the compounds of formula I may provide improved efficiency, stability, manufacturability, or spectral characteristics of electroluminescent devices.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/424,892 filed on Mar. 20, 2012, which claims priority to U.S.Provisional Patent Application No. 61/467,412 filed Mar. 25, 2011 andU.S. Provisional Patent Application No. 61/557,933 filed Nov. 10, 2011,wherein the contents of all applications are herein incorporated byreference.

FIELD OF THE INVENTION

The present invention relates to compounds of formula I, a process fortheir production and their use in electronic devices, especiallyelectroluminescent devices. When used as hole transport material inelectroluminescent devices, the compounds of formula I may provideimproved efficiency, stability, manufacturability, or spectralcharacteristics of electroluminescent devices.

BACKGROUND OF THE INVENTION

Khan, Misbahul Ain; Ribeiro, Vera Lucia Teixeira, Pakistan Journal ofScientific and Industrial Research 43 (2000) 168-170 describes thesynthesis of benzimidazo[1,2-a]benzimadozoles

(R=H, Me, Et) by trialkyl phosphite-induced deoxygenation andthermolysis of 1-(o-nitrophenyl)- and 1-(o-azidophenyl)benzimidazoles.

Pedro Molina et al. Tetrahedron (1994) 10029-10036 reports that azaWittig-type reaction of bis(iminophosphoranes), derived frombis(2-aminophenyl)amine with two equivalents of isocyanate directlyprovided benzimidazo[1,2,a]benzimidazole derivatives.

(R=R′=

R=

and R=

R=iso-propyl and R′=ethyl)

-   Kolesnikova, I. V.; Zhurnal Organicheskoi Khimii 25 (1989) 1689-95    describes the synthesis of 5H-benzimidazo[1,2-a]benzimidazole    1,2,3,4,7,8,9,10-octafluoro-5-(2,3,4,5,6-pentafluorophenyl).

-   Achour, Reddouane; Zniber, Rachid, Bulletin des Societes Chimiques    Beiges 96 (1987) 787-92 describes the synthesis of    benzimidazobenzimidazoles

(R=H, —CH(CH₃)₂) which were prepared from benzimidazolinone derivatives.

-   Hubert, Andre J.; Reimlinger, Hans, Chemische Berichte 103 (1970)    2828-35 describes the synthesis of benzimidazobenzimidazoles

(R=H, CH₃,

JP2001160488 describes an electroluminescent element which has alight-emitting layer having a single-layer or multiple-layer organiccompound film between opposing anode and cathode, wherein at least onelayer of the organic compound film contains at least one kind ofcompounds indicated by formula

The following compounds are explicitly disclosed:

US20100244006 relates to an organic electroluminescent device whichincludes: a cathode; an anode; and at least one organic layer betweenthe cathode and the anode. The at least one organic layer includes alight emitting layer containing at least one light emitting material. Acompound represented by the following formula

is contained in the at least one organic layer. where n stands for aninteger of 2 or greater, L represents an n-valent linking group, and R¹,R², R³, and R⁴ each independently represents a hydrogen atom or asubstituent.

The compounds described in US20100244006 are preferably used in as hostin the light emitting layer.

represents an example of a compound disclosed in US20100244006.

KR1020110008784 relates to novel organic luminescent compounds offormula

and organic electroluminescence devices including the same.

US2005079387 relates to an imidazole ring containing compound of formulaAr₁-Ar₂-Ar₃, (blue luminescent host compound) and an organicelectroluminescence (EL) display device using the same.

Ar₂ is selected from the group consisting of

each of Ar₁ and Ar₃ is independently selected from

wherein X′ is O, or S.

US2005074632 relates to an imidazole ring containing compound of formula

and an organic electroluminescence (EL) display device using the same.In particular, the imidazole ring-containing compound may be used aloneor in combination with a dopant as a material for organic films such asan electroluminescent layer.

A is selected from the group consisting of

—N(R₁₃R₁₄), and

B is selected from the group consisting of

X is selected from the group consisting of —O—, —S—, —Se— and —NH—.

JP2007180147 relates to an organic electroluminescence element,sandwiched by an anode and a cathode and containing at least alight-emitting layer, which contains a compound represented by generalformula 1, 2, 3 or 4:

Ar₁-Ar₄=aromatic group or aromatic heterocyclic group; R₁-R₅=H orsubstituent; Z₁=residue required to form heterocyclic ring of 5 or 6members; L₁, L₂=bond or coupling group; and X₁-X₁₆=carbon or nitrogen. Anew ring can be formed in one portion of Ar₁ and Ar₂, and Ar₃ and Ar₄.

The following compounds are explicitly disclosed:

U.S. Pat. No. 6,551,723 relates to an organic electroluminescenceelement comprising a light-emitting layer or a plurality of organiccompound thin layers containing a light-emitting layer between a pair ofelectrodes, wherein at least one layer in the organicelectroluminescence element comprises at least one heterocyclic compoundrepresented by formula (I) to (VII):

R₁₁, R₁₂, R₁₃, R₂₁, R₂₂, R₃₁, R₃₂, R₄₁, R₄₂, R₅₁, R₆₁, and R₇₁ are eachindependently a hydrogen atom or substituent; Z₁, Z₂, Z₃, Z₄, Z₅, Z₆,and Z₇ are a group of atoms that are necessary for forming a 5- or6-member ring. The compounds represented by formula (I) to (VII) areparticularly added to a light-emitting layer and/or electroninjection/transporting layer. The following compounds are explicitlydisclosed:

WO2011160757 relates to an electronic device comprising an anode,cathode and at least one organic layer which contains a compound offormulae

wherein X may be a single bond and L may be a divalent group. Thefollowing 4H-Imidazo[1,2-a]imidazole compounds are explicitly disclosed:

Notwithstanding these developments, there remains a need for organiclight emitting devices comprising new hole transport materials toprovide improved efficiency, stability, manufacturability, and/orspectral characteristics of electroluminescent devices.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention, with respect tothe aforementioned prior art, to provide further materials suitable foruse in OLEDs and further applications in organic electronics. Moreparticularly, it should be possible to provide hole transport materials,electron/exciton blocker materials and matrix materials for use inOLEDs. The materials should be suitable especially for OLEDs whichcomprise at least one phosphorescence emitter, especially at least onegreen emitter or at least one blue emitter. Furthermore, the materialsshould be suitable for providing OLEDs which ensure good efficiencies,good operative lifetimes and a high stability to thermal stress, and alow use and operating voltage of the OLEDs.

Certain imidazole derivatives

especially

(R^(9′) has the meaning of R⁹, R^(10′) has the meaning of R¹⁰) are foundto be suitable for use in organo-electroluminescent devices. Inparticular, certain imidazole derivatives are suitable hole transportingmaterials, or host materials for phosphorescent emitters with goodefficiency and durability.

DETAILED DESCRIPTION OF THE INVENTION

Said object has been solved by compounds of the formula

whereinX⁶ is —N═ and X⁷ is —NR¹—, orX⁷ is ═N— and X⁶ is —NR¹—,R¹ is a group of formula -A¹-(A²)_(p)-(A³)_(q)-(A⁴)_(r)-R⁶,p is 0, or 1, q is 0, or 1, r is 0, or 1,A¹, A², A³ and A⁴ are independently of each other a C₆-C₂₄arylen group,which can optionally be substituted by G, or a C₂-C₃₀heteroarylen group,which can optionally be substituted by G; whereinthe groups A¹, A², A³ and A⁴ may be interrupted by one, or more groups—(SiR⁷R⁸)—;R⁶ is H, a group —(SiR²⁰R²¹R²²), a C₆-C₂₄aryl group, which canoptionally be substituted by G, or a C₂-C₃₀heteroaryl group, which canoptionally be substituted by G;R⁷ and R⁸ are independently of each other a C₁-C₂₅alkyl group, or aC₆-C₂₄aryl group, which can optionally be substituted by G;X¹ is N, or CR⁹;X² is N, or CR¹⁰,R⁹, R¹⁰, R^(9′) and R^(10′) are independently of each other H, aC₁-C₂₅alkyl group, which can optionally be substituted by E and orinterrupted by D; a C₆-C₂₄aryl group, which can optionally besubstituted by G, or a C₂-C₃₀heteroaryl group, which can optionally besubstituted by G; or R⁹ and R¹⁰ and/or R^(9′) and R^(10′) together forma ring, which can optionally be substituted,R²⁰, R²¹ and R²² are independently of each other a C₁-C₂₅alkyl group, ora C₆-C₂₄aryl group, which can optionally be substituted by G; D is —CO—,—COO—, —S—, —SO—, —SO₂—, —O—, —NR⁶⁵—, —SiR⁷⁰R⁷¹—, —POR⁷²—, —CR⁶³═CR⁶⁴—,or —C≡C—,E is —OR⁶⁹, —SR⁶⁹, —NR⁶⁵R⁶⁶, —COR⁶⁸, —COOR⁶⁷, —CONR⁶⁶R⁶⁶, —CN, orhalogen, G is E, or a C₁-C₁₈alkyl group, a C₆-C₂₄aryl group, aC₆-C₂₄aryl group, which is substituted by F, C₁-C₁₈alkyl, or C₁-C₁₈alkylwhich is interrupted by O; a C₂-C₃₀heteroaryl group, or aC₂-C₃₀heteroaryl group, which is substituted by F, C₁-C₁₈alkyl, orC₁-C₁₈alkyl which is interrupted by O;R⁶³ and R⁶⁴ are independently of each other C₆-C₁₈aryl; C₆-C₁₈aryl whichis substituted by C₁-C₁₈alkyl, C₁-C₁₈alkoxy; C₁-C₁₈alkyl; or C₁-C₁₈alkylwhich is interrupted by —O—;R⁶⁵ and R⁶⁶ are independently of each other a C₆-C₁₈aryl group; aC₆-C₁₈aryl which is substituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy; aC₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which is interrupted by —O—;orR⁶⁵ and R⁶⁶ together form a five or six membered ring,R⁶⁷ is a C₆-C₁₈aryl group; a C₆-C₁₈aryl group, which is substituted byC₁-C₁₈alkyl, or C₁-C₁₈alkoxy; a C₁-C₁₈alkyl group; or a C₁-C₁₈alkylgroup, which is interrupted by —O—,R⁶⁸ is H; a C₆-C₁₈aryl group; a C₆-C₁₈aryl group, which is substitutedby C₁-C₁₈alkyl, or C₁-C₁₈alkoxy; a C₁-C₁₈alkyl group; or a C₁-C₁₈alkylgroup, which is interrupted by —O—,R⁶⁹ is a C₆-C₁₈aryl; a C₆-C₁₈aryl, which is substituted by C₁-C₁₈alkyl,or C₁-C₁₈alkoxy; a C₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which isinterrupted by —O—,R⁷⁰ and R⁷¹ are independently of each other a C₁-C₁₈alkyl group, aC₆-C₁₈aryl group, or a C₆-C₁₈aryl group, which is substituted byC₁-C₁₈alkyl, andR⁷² is a C₁-C₁₈alkyl group, a C₆-C₁₈aryl group, or a C₆-C₁₈aryl group,which is substituted by C₁-C₁₈alkyl; with the proviso that the followingcompounds are excluded:

In particular said object has been solved by compounds of formula

very especially

whereinX⁶ is —N═ and X⁷ is —NR¹—, orX⁷ is ═N— and X⁶ is —NR¹—, whereinR¹ is a group of formula -A¹-(A²)_(p)-(A³)_(q)-(A⁴)_(r)-R⁶,p is 0, or 1, q is 0, or 1, r is 0, or 1,A¹, A², A³ and A⁴ are independently of each other a C₆-C₂₄arylen group,which can optionally be substituted by G, or a C₂-C₃₀heteroarylen group,which can optionally be substituted by G; whereinthe groups A¹, A², A³ and A⁴ may be interrupted by one, or more groups—(SiR⁷R⁸)—;R², R³, R⁴ and R⁸ are independently of each other H, a C₁-C₂₅alkylgroup, which can optionally be substituted by E and or interrupted by D;a C₆-C₂₄aryl group, which can optionally be substituted by G, or aC₂-C₃₀heteroaryl group, which can optionally be substituted by G;R⁶ is H, a group —(SiR²⁰R²¹R²²), a C₆-C₂₄aryl group, which canoptionally be substituted by G, or a C₂-C₃₀heteroaryl group, which canoptionally be substituted by G; R⁷ and R⁸ are independently of eachother a C₁-C₂₅alkyl group, or a C₆-C₂₄aryl group, which can optionallybe substituted by G;X¹ is N, or CR⁹,X² is N, or CR¹⁰,R⁹ and R¹⁰ are independently of each other H, a C₁-C₂₅alkyl group, whichcan optionally be substituted by E and or interrupted by D; a C₆-C₂₄arylgroup, which can optionally be substituted by G, or a C₂-C₃₀heteroarylgroup, which can optionally be substituted by G; orR⁹ and R¹⁰ together form a ring, which can optionally be substituted,R²⁰, R²¹ and R²² are independently of each other a C₁-C₂₅alkyl group, ora C₆-C₂₄aryl group, which can optionally be substituted by G; D is —CO—,—COO—, —S—, —SO—, —SO₂—, —O—, —NR⁶⁵—, —SiR⁷⁰R⁷¹—, —POR⁷²—, —CR⁶³═CR⁶⁴—,or —CC—,E is —OR⁶⁹, —SR⁶⁹, —NR⁶⁵R⁶⁶, —COR⁶⁸, —COOR⁶⁷, —CONR⁶⁸R⁶⁶, —CN, orhalogen,G is E, or a C₁-C₁₈alkyl group, a C₆-C₂₄aryl group, a C₆-C₂₄aryl groupwhich is substituted by C₁-C₁₈alkyl;R⁶³ and R⁶⁴ are independently of each other C₆-C₁₈aryl; C₆-C₁₈aryl whichis substituted by C₁-C₁₈alkyl, C₁-C₁₈alkoxy; C₁-C₁₈alkyl; or C₁-C₁₈alkylwhich is interrupted by —O—;R⁶⁵ and R⁶⁶ are independently of each other a C₆-C₁₈aryl group; aC₆-C₁₈aryl which is substituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy; aC₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which is interrupted by —O—;orR⁶⁵ and R⁶⁶ together form a five or six membered ring,R⁶⁷ is a C₆-C₁₈aryl group; a C₆-C₁₈ aryl group, which is substituted byC₁-C₁₈alkyl, or C₁-C₁₈alkoxy; a C₁-C₁₈alkyl group; or a C₁-C₁₈alkylgroup, which is interrupted by —O—,R⁶⁸ is H; a C₆-C₁₈aryl group; a C₆-C₁₈aryl group, which is substitutedby C₁-C₁₈alkyl, or C₁-C₁₈alkoxy; a C₁-C₁₈alkyl group; or a C₁-C₁₈alkylgroup, which is interrupted by —O—,R⁶⁹ is a C₆-C₁₈ aryl; a C₆-C₁₈aryl, which is substituted by C₁-C₁₈alkyl,or C₁-C₁₈alkoxy; a C₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which isinterrupted by —O—,R⁷⁰ and R⁷¹ are independently of each other a C₁-C₁₈alkyl group, aC₆-C₁₈ aryl group, or a C₆-C₁₈aryl group, which is substituted byC₁-C₁₈alkyl, andR⁷² is a C₁-C₁₈alkyl group, a C₆-C₁₈aryl group, or a C₆-C₁₈aryl group,which is substituted by C₁-C₁₈alkyl.

The compounds of the present invention may be used forelectrophotographic photoreceptors, photoelectric converters, organicsolar cells (organic photovoltaics), switching elements, such as organictransistors, for example, organic FETs and organic TFTs, organic lightemitting field effect transistors (OLEFETs), image sensors, dye lasersand electroluminescent devices, such as, for example, organiclight-emitting diodes (OLEDs).

Accordingly, a further subject of the present invention is directed toan electronic device, comprising a compound according to the presentinvention. The electronic device is preferably an electroluminescentdevice.

The compounds of formula I can in principal be used in any layer of anEL device, but are preferably used as host, hole transport and electronblocking material. Particularly, the compounds of formula I are used ashost material for blue light emitting phosphorescent emitters.

Hence, a further subject of the present invention is directed to an holetransport layer, comprising a compound of formula I according to thepresent invention.

A further subject of the present invention is directed to an emittinglayer, comprising a compound of formula I according to the presentinvention. In said embodiment a compound of formula I is preferably usedas host material in combination with a phosphorescent emitter.

A further subject of the present invention is directed to a electronblocking layer, comprising a compound of formula I according to thepresent invention.

The compound of formula I is especially a compound of formula

(I), whereinX⁶ is —N═ and X⁷ is —NR¹—, orX⁷ is ═N— and X⁶ is —NR¹—,R², R³, R⁴ and R⁵ are independently of each other H, a C₁-C₂₅alkylgroup, which can optionally be substituted by E and or interrupted by D;a C₆-C₂₄aryl group, which can optionally be substituted by G, or aC₂-C₃₀heteroaryl group, which can optionally be substituted by G;X¹, X², R¹, E, D and G are as defined above.

The compound of formula I may be a compound of formula

X⁶ is —N═ and X⁷ is —NR¹—, or X⁷ is ═N— and X⁶ is —NR¹—. Especiallypreferred are compounds of formula Id, wherein R⁹ and R¹⁰ together forma ring

wherein R¹¹, R¹², R¹³ and R¹⁴ are as defined below. R¹¹, R¹², R¹³ andR¹⁴ are preferably H. R², R³, R⁴ and R⁵ are preferably H.

In a preferred embodiment the compound of formula (I) is a compound offormula

In another preferred embodiment the compound of formula (I) is acompound of formula

Preferably, the compound of formula I is a compound of formula

Compounds of formula Ib′ and Id′ are preferred. Compounds of formula Id′are more preferred. Even more preferred are compounds of formula Id′,wherein R⁹ and R¹⁰ together form a ring

wherein R¹¹, R¹², R¹³ and R¹⁴ are as defined below. R¹¹, R¹², R¹³ andR¹⁴ are preferably H.

R², R³, R⁴ and R⁹ are preferably H.

Compounds of formula I, which are not axially symmetric, such as, forexample, compounds of formula Id′, wherein R⁹ and R¹⁰ are H, can existin two isomeric forms:

Reference is made to Example 2, which describes the synthesis of amixture of the following compounds:

4H-imidazo[1,2-a]benzimidazole is prepared as described in ARKIVOC 2002(v) 48-61. Ullmann reaction of 4H-imidazo[1,2-a]benzimidazole with1-bromo-3-iodo-benzene give two isomers in a ratio of approximately 1 to1.

R²⁰, R²¹ and R²² are preferably C₁-C₁₈alkyl, such as methyl, ethyl,n-propyl, iso-propyl, n-butyl, isobutyl, sec-butyl, t-butyl,2-methylbutyl, n-pentyl, isopentyl, n-hexyl, 2-ethylhexyl, or n-heptyl,C₆-C₁₄aryl, such as phenyl, naphthyl, or biphenylyl, or, C₆-C₁₄arylwhich is substituted by G, such as —C₆H₄OCH₃, —C₆H₄OCH₂CH₃,—C₆H₃(OCH₃)₂,or —C₆H₃(OCH₂CH₃)₂, —C₆H₄CH₃, —C₆H₃(CH₃)₂, —C₆H₂(CH₃)₃, or —C₆H₄tBu.

R⁹ and R¹⁰ are preferably H, or C₆-C₁₄aryl, such as phenyl, naphthyl, orbiphenylyl, which may optionally be substituted by one, or moreC₁-C₈alkyl groups; or C₂-C₃₀heteroaryl, such as, for example,dibenzofuranyl, which may optionally be substituted by one, or moreC₁-C₈alkyl groups.

In a preferred embodiment the present invention is directed to compoundsof formula

especially

whereinX⁶ is —N═ and X⁷ is —NR¹—, orX⁷ is ═N— and X⁶ is —NR¹—,R¹¹, R¹², R¹³ and R¹⁴ are independently of each other H, a C₁-C₂₅alkylgroup, which can optionally be substituted by E and or interrupted by D;a C₆-C₂₄aryl group, which can optionally be substituted by G, or aC₂-C₃₀heteroaryl group, which can optionally be substituted by G, and E,D, G, R¹, R², R³, R⁴ and R⁵ are as defined above.

In a preferred embodiment the compound of formula (II) is a compound offormula

In another preferred embodiment the compound of formula (II) is acompound of formula

Compounds of formula II are even more preferred, wherein R², R³, R⁴, R⁵,R¹¹, R¹², R¹³ and R¹⁴ are H and R¹ is as defined above:

R⁶ may be a C₆-C₂₄aryl group, which can optionally be substituted by G,or a C₂-C₃₀heteroaryl group, which can optionally be substituted by G

The C₆-C₂₄aryl group R⁶, which optionally can be substituted by G, istypically phenyl, 4-methylphenyl, 4-methoxyphenyl, naphthyl, especially1-naphthyl, or 2-naphthyl, biphenylyl, terphenylyl, pyrenyl, 2- or9-fluorenyl, phenanthryl, or anthryl, which may be unsubstituted orsubstituted.

The C₂-C₃₀heteroaryl group R⁶, which optionally can be substituted by G,represents a ring with five to seven ring atoms or a condensed ringsystem, wherein nitrogen, oxygen or sulfur are the possible heteroatoms, and is typically a heterocyclic group with five to 30 atomshaving at least six conjugated π-electrons such as thienyl,benzothiophenyl, dibenzothiophenyl, thianthrenyl, furyl, furfuryl,2H-pyranyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl,phenoxythienyl, pyrrolyl, imidazolyl, pyrazolyl, pyridyl, bipyridyl,triazinyl, pyrimidinyl, pyrazinyl, pyridazinyl, indolizinyl, isoindolyl,indolyl, indazolyl, purinyl, quinolizinyl, chinolyl, isochinolyl,phthalazinyl, naphthyridinyl, chinoxalinyl, chinazolinyl, cinnolinyl,pteridinyl, carbolinyl, benzotriazolyl, benzoxazolyl, phenanthridinyl,acridinyl, pyrimidinyl, phenanthrolinyl, phenazinyl, isothiazolyl,phenothiazinyl, isoxazolyl, furazanyl, 4-imidazo[1,2-a]benzimidazoyl,5-benzimidazo[1,2-a]benzimidazoyl, carbazolyl, or phenoxazinyl, whichcan be unsubstituted or substituted. In addition, the C₂-C₃₀heteroarylgroup R⁶ includes 4H-[1,2,4]triazolo[1,5-a]benzimidazoyl, which can beunsubstituted or substituted.

The C₆-C₂₄aryl and C₂-C₃₀heteroaryl groups may be substituted by G andare preferably substituted by one, or more C₁-C₈alkyl groups.

Preferred C₂-C₃₀heteroaryl groups are pyridyl, triazinyl, pyrimidinyl,4-imidazo[1,2-a]benzimidazoyl, 5-benzimidazo[1,2-a]benzimidazoyl,carbazolyl, dibenzofuranyl, which can be unsubstituted or substitutedespecially by C₆-C₁₀aryl, or C₆-C₁₀aryl, which is substituted byC₁-C₄alkyl, or C₂-C₅heteroaryl. 4H-[1,2,4]triazolo[1,5-a]benzimidazoylrepresents also a preferred C₂-C₃₀heteroaryl group R⁶.

A¹, A², A³ and A⁴ are independently of each other a C₆-C₂₄arylen group,which can optionally be substituted by G, or a C₂-C₃₀heteroarylen group,which can optionally be substituted by G. The C₆-C₂₄arylen groups A¹,A², A³ and A⁴, which optionally can be substituted by G, are typicallyphenylene, 4-methylphenylene, 4-methoxyphenylene, naphthylene,especially 1-naphthylene, or 2-naphthylene, biphenylylene,terphenylylene, pyrenylene, 2- or 9-fluorenylene, phenanthrylene, oranthrylene, which may be unsubstituted or substituted.

The C₂-C₃₀heteroarylen groups A¹, A², A³ and A⁴, which optionally can besubstituted by G, represent a ring with five to seven ring atoms or acondensed ring system, wherein nitrogen, oxygen or sulfur are thepossible hetero atoms, and is typically a heterocyclic group with fiveto 30 atoms having at least six conjugated-electrons such as thienylene,benzothiophenylene, dibenzothiophenylene, thianthrenylene, furylene,furfurylene, 2H-pyranylene, benzofuranylene, isobenzofuranylene,dibenzofuranylene, phenoxythienylene, pyrrolylene, imidazolylene,pyrazolylene, pyridylene, bipyridylene, triazinylene, pyrimidinylene,pyrazinylene, pyridazinylene, indolizinylene, isoindolylene, indolylene,indazolylene, purinylene, quinolizinylene, chinolylene, isochinolylene,phthalazinylene, naphthyridinylene, chinoxalinylene, chinazolinylene,cinnolinylene, pteridinylene, carbolinylene, benzotriazolylene,benzoxazolylene, phenanthridinylene, acridinylene, pyrimidinylene,phenanthrolinylene, phenazinylene, isothiazolylene, phenothiazinylene,isoxazolylene, furazanylene, carbazolylene, or phenoxazinylene, whichcan be unsubstituted or substituted.

Preferred C₆-C₂₄arylen groups are 1,3-phenylene, 3,3′-biphenylylene,3,3′-m-terphenylene, 2- or 9-fluorenylene, phenanthrylene, which may beunsubstituted or substituted.

Preferred C₂-C₃₀heteroarylen groups are pyridylene, triazinylene,pyrimidinylene, carbazolylene, dibenzofuranylene which can beunsubstituted or substituted, especially by C₆-C₁₀aryl, C₆-C₁₀aryl whichis substituted by C₁-C₄alkyl, or C₂-C₅heteroaryl.

More preferred C₂-C₃₀heteroarylen groups are carbazolylene anddibenzofuranylene which optionally can be substituted by C₆-C₁₀aryl,which can optionally be substituted by one, or more C₁-C₄alkyl groups.

The C₆-C₂₄arylen and C₂-C₃₀heteroarylen groups maybe substituted by Gand are preferably substituted by one, or more C₁-C₈alkyl groups.

As the term “a C₂-C₃₀heteroaryl group” includes, for example, groups offormula

especially

groups A¹, A², A³ and A⁴ can be, for example, substituted by one, ormore groups of formula

especially

resulting, for example, in compounds of formula

[n is 2, or 3, especially 2], wherein A¹ is a group of formula

and R⁶ is a group of formula

especially

In addition, R⁶ may be a group of formula

X^(6′) is —N═ and X^(7′) is —N<, or X^(7′) is ═N— and X^(6′) is —N<. m3is 0, or an integer of 1 to 4. m4 is 0, or an integer 1 to 3.

R¹ is preferably a group of formula -A¹-(A²)_(p)-(A³)_(q)-(A⁴)_(r)-R⁶,such as, for example, -A¹-R⁶, -A¹-A²-R⁶, -A¹-A²-A³-R⁶, -A¹-A²-A³-A⁴-R⁶,or

wherein A¹, A², A³ and A⁴ are independently of each other a group offormula

whereinm5 is 0, or an integer of 1 to 4,m2 is 0, or an integer 1 to 3,X³ is —O—, —S—, or —NR¹⁵—,R⁷ and R⁸ are a C₁-C₁₈alkyl group,R¹⁵ is a C₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which is interruptedby —O—; a C₆-C₁₈aryl group; a C₆-C₁₈aryl group, which is substituted byone, or more C₁-C₁₈alkyl groups, or C₁-C₁₈alkoxy groups; aC₂-C₂₀heteroaryl group, or a C₂-C₂₀heteroaryl group, which issubstituted by one, or more C₁-C₁₈alkyl groups,R⁴¹ may be the same, or different in each occurrence and is F,C₁-C₁₈alkyl, C₁-C₁₈alkyl which is substituted by E and/or interrupted byD, C₆-C₂₄aryl, C₆-C₂₄aryl which is substituted by G, C₂-C₂₀heteroaryl,or C₂-C₂₀heteroaryl which is substituted by G, andR⁶, p, q, r, E, D and G are as defined above, or below.

A group of formula

is less preferred than groups of formula

More preferably, A¹, A², A³ and A⁴ are independently of each other agroup of formula

wherein R¹⁵ is a C₆-C₁₈aryl group; or a C₆-C₁₈aryl group, which issubstituted by one, or more C₁-C₁₈alkyl groups.

R¹⁵ is preferably a group of formula

wherein R¹⁰⁰ is a C₁-C₈alkyl group.

Groups -A¹-(A²)_(p)-(A³)_(q)-(A⁴)_(r)- are preferred, wherein at leastone of A¹, A², A³ and A⁴ is a group of formula

wherein Y is —O—, —S—, or —NR¹⁵—, wherein R¹⁵ is as defined above.Groups -A¹-(A²)_(p)-(A³)_(q)-(A⁴)_(r)-are more preferred, wherein atleast one of A¹,A², A³ and A⁴ is a group of formula

Examples of preferred groups -A¹-(A²)_(p)-(A³)_(q)-(A⁴)_(r)-are shownbelow:

Additional examples of a group of formula-A¹-(A²)_(p)-(A³)_(q)-(A⁴)_(r)-are groups of formula

In another preferred embodiment R¹ is a group of formula-A¹-(A²)_(p)-(A³)_(q)-(A⁴)_(r)-R⁶, such as, for example, -A¹-R⁶,-A¹-A²-R⁶, -A¹-A²-A³-R⁶, or -A¹-A²-A³-A⁴-R⁶, wherein at least one of thegroups A¹, A², A³ and A⁴ is a group of formula

and the others are independently of each other a group of formula

wherein R¹⁵ is a C₆-C₁₈ aryl group; or a C₆-C₁₈ aryl group, which issubstituted by one, or more C₁-C₁₈alkyl groups. Examples of preferredgroups -A¹-(A²)_(p)-(A³)_(q)-(A⁴)_(r)-are shown below:

R⁶ is especially a group of formula

very especially a group of formula

R², R³, R⁴, R⁵, R¹¹, R¹², R¹³, R¹⁴, R⁴³ and m3 are as defined above.

In a preferred embodiment of the present invention R⁶ is a group offormula

(X^(6′) is —N═ and X^(7′) is —N<, or X^(7′) is ═N— and X^(6′) is —N<),especially

or a group —(SiR²⁰R²¹R²²), wherein R², R³, R⁴, R⁵, R¹¹, R¹², R¹³ and R¹⁴are independently of each other H, a C₁-C₂₅alkyl group, which canoptionally be substituted by E and or interrupted by D; a C₆-C₂₄arylgroup, which can optionally be substituted by G, or a C₂-C₃₀heteroarylgroup, which can optionally be substituted by G,R¹⁶ is a C₆-C₁₈aryl group; or a C₆-C₁₈aryl group, which is substitutedby one, or more C₁-C₁₈alkyl groups.R²⁰, R²¹ and R²² are independently of each other a C₆-C₁₈aryl group; ora C₆-C₁₈aryl group, which is substituted by one, or more C₁-C₁₈alkylgroups,R⁴³ may be the same, or different in each occurrence and is F,C₁-C₁₈alkyl, C₁-C₁₈alkyl which is substituted by E and/or interrupted byD, C₆-C₂₄aryl, C₆-C₂₄aryl which is substituted by G, C₂-C₂₀heteroaryl,or C₂-C₂₀heteroaryl which is substituted by G,m3 is 0, or an integer of 1 to 4, m4 is 0, or an integer of 1 to 3, andE, D, and G are as defined above, or below.D is preferably —CO—, —COO—, —S—, —SO—, —SO₂—, —O—, —NR⁶⁵—, wherein R⁶⁵is C₁-C₁₈alkyl, such as methyl, ethyl, n-propyl, iso-propyl, n-butyl,isobutyl, or sec-butyl, or C₆-C₁₄aryl, such as phenyl, tolyl, naphthyl,or biphenylyl.E is preferably —OR⁶⁹; —SR⁶⁹; —NR⁶⁵R⁶⁵; —COR⁶⁸; —COOR⁶⁷; —CONR⁶⁵R⁶⁵; or—CN; wherein R⁶⁵, R⁶⁷, R⁶⁸ and R⁶⁹ are independently of each otherC₁-C₁₈alkyl, such as methyl, ethyl, n-propyl, iso-propyl, n-butyl,isobutyl, sec-butyl, hexyl, octyl, or 2-ethyl-hexyl, or C₆-C₁₄aryl, suchas phenyl, tolyl, naphthyl, or biphenylyl.G has the same preferences as E, or is C₁-C₁₈alkyl, such as methyl,ethyl, n-propyl, iso-propyl, n-butyl, isobutyl, sec-butyl, hexyl, octyl,or 2-ethyl-hexyl, or is C₁-C₁₈perfluoroalkyl, such, for example, —CF₃.R², R³, R⁴, R⁵, R¹¹, R¹², R¹³ and R¹⁴ are preferably H.R⁴³ is preferably H, or C₆-C₁₄aryl, such as phenyl, tolyl, naphthyl, orbiphenylyl, which may optionally be substituted.m3 is preferably 0, or 1, most preferred 0. m4 is preferably 0, or 1,most preferred 0.M2 is preferably 0, or 1, most preferred 0. m5 is preferably 0, or 1,most preferred 0.R²⁰, R²¹ and R²² are preferably a group of formula

wherein R¹⁰⁰ is a C₁-C₈alkyl group.

More preferably, R⁶ is a group of formula

wherein R¹⁶ is a C₆-C₁₈aryl group; or a C₆-C₁₈aryl group, which issubstituted by one, or more C₁-C₁₈alkyl groups.R¹⁶ is preferably a group of formula

wherein R¹⁰⁰ is a C₁-C₈alkyl group.

In a preferred embodiment the present invention is directed to compoundsof formula

wherein R¹ is a group of formula -A¹-(A²)_(p)-(A³)_(q)-(A⁴)_(r)-R⁶,A¹, A², A³ and A⁴ are independently of each other a group of formula

R⁶ is a group of formula

andR¹⁵ is a group of formula

wherein R¹⁰⁰ is a C₁-C₈alkyl group, and p, q and r are as defined above.

In said embodiment the group of formula-A¹-(A²)_(p)-(A³)_(q)-(A⁴)_(r)-is especially a group of formula

Additional examples of a group of formula-A¹-(A²)_(p)-(A³)_(q)-(A⁴)_(r)-are groups of formula

The at present most preferred groups of formula-A¹-(A²)_(p)-(A³)_(q)-(A⁴)_(r)-are the groups of formula (IVa), (IVb),(IVe), (IVl), (IVk), (IVs), (IVv) and (VIj).

Examples of preferred compounds are compounds A-1 to A-20, especiallyA-1 to A-19 shown in claim 8, and compounds A-21 to A-32 shown in thetable below:

Cpd. L¹ ²⁾ R⁶ A-21

A-22

A-23

A-24

A-25

A-26

A-27

A-28

A-29

A-30

A-31

A-32

In another preferred embodiment the present invention is directed tocompounds of formula

wherein R¹ is a group of formula -A¹-(A²)_(p)-(A³)_(q)-(A⁴)_(r)-R⁶,wherein at least one of the groups A¹, A², A³ and A⁴ is a group offormula

and the others are independently of each other a group of formula

R⁶ is a group of formula

andR¹⁶ is a group of formula

wherein R¹⁰⁰ is a C₁-C₈alkyl group, and p, q and r are as defined above.

In said embodiment the group of formula-A¹-(A²)_(p)-(A³)_(q)-(A⁴)_(r)-is especially a group of formula

The at present most preferred groups of formula-A¹-(A²)_(p)-(A³)_(q)-(A⁴)_(r)-are the groups of formula (IVa), (IVb),(IVe), (IVl), (IVk), (IVs), (IVv) and (VIj).

In case the compounds of formula I are used as host material for blue,or green phosphorescent emitters, or as electron/exciton blockingmaterial, groups A¹-(A²)_(p)-(A³)_(q)-(A⁴)_(r)-are less preferred, whichcontain a group of formula

i.e. groups of formula (IVp) and (IVr).

Examples of preferred compounds are compounds C-1 to C-78 shown in thetable below.

Cpd. L¹ ²⁾ R⁶ C-1 

C-2 

C-3 

C-4 

C-5 

C-6 

C-7 

C-8 

C-9 

C-10

C-11

C-12

C-13

C-14

C-15

C-16

C-17

C-18

C-19

C-20

C-21

C-22

C-23

C-24

C-25

C-26

C-27

C-28

C-29

C-30

C-31

C-32

C-33

C-34

C-35

C-36

C-37

C-38

C-39

C-40

C-41

C-42

C-43

C-44

C-45

C-46

C-47

C-48

C-49

C-50

C-51

C-52

C-53

C-54

C-55

C-56

C-57

C-58

C-59

C-60

C-61

C-62

C-63

C-64

C-65

C-66

C-67

C-68

C-69

C-70

C-71

C-72

C-73

C-74

C-75

C-76

C-77

C-78

In another preferred embodiment the present invention is directed tocompounds of formula

In another preferred embodiment the present invention is directed tocompounds of formula

In said embodiments R¹ is a group of formula-A¹-(A²)_(p)-(A³)_(q)-(A⁴)_(r)-R⁶, wherein

A¹, A², A³ and A⁴ are independently of each other a group of formula

R⁶ is a group of formula

R¹⁵ and R¹⁶ are a group of formula

wherein R¹⁰⁰ is a C₁-C₈alkyl group, and p, q and r are as defined above.In addition, A¹, A², A³ and A⁴ may represent a group of formula

In addition, R⁶ may represent a group of formula

In said embodiment the group of formula -A¹-(A²_(p)-(A³)_(q)-(A⁴)_(r)-is especially a group of formula

In addition, the group of formula -A¹-(A²)_(p)-(A³)_(q)-(A⁴)_(r)-may bea group of formula

Examples of preferred compounds are compounds B-1 to B-5, especially B-1to B-4 shown in claim 9 and compounds B-6 to B-35 shown in the tablebelow.

Cpd. L¹ ²⁾ R⁶ B-6

B-7

B-8

B-9

B-10

B-11

B-12

B-13

B-14

B-15

B-16

B-17

B-18

B-19

B-20

B-21

B-22

B-23

B-24

B-25

B-26

B-27

B-28

B-29

B-30

B-31

B-32

B-33

B-34

B-35

Additional examples of preferred compounds are compounds J-1 to J-35,K-1 to K-35 and L-1 to L-35 shown in the tables below.

Cpd. L¹ ³⁾ R⁶ J-1

J-2

J-3

J-4

J-5

J-6

J-7

J-8

J-9

J-10

J-11

J-12

J-13

J-14

J-15

J-16

J-17

J-18

J-19

J-20

J-21

J-22

J-23

J-24

J-25

J-26

J-27

J-28

J-29

J-30

J-31

J-32

J-33

J-34

J-35

Cpd. L¹ ³⁾ R⁶ K-1 

K-2 

K-3 

K-4 

K-5 

K-6 

K-7 

K-8 

K-9 

K-10

K-11

K-12

K-13

K-14

K-15

K-16

K-17

K-18

K-19

K-20

K-21

K-22

K-23

K-24

K-25

K-26

K-27

K-28

K-29

K-30

K-31

K-32

K-33

K-34

K-35

Cpd. L¹ ⁴⁾ R⁶ L-1 

L-2 

L-3 

L-4 

L-5 

L-6 

L-7 

L-8 

L-9 

L-10

L-11

L-12

L-13

L-14

L-15

L-16

L-17

L-18

L-19

L-20

L-21

L-22

L-23

L-24

L-25

L-26

L-27

L-28

L-29

L-30

L-31

L-32

L-33

L-34

L-35

In another preferred embodiment the present invention is directed tocompounds of formula

wherein R¹ is a group of formula -A¹-(A²)_(p)-(A³)_(q)-(A⁴)_(r)-R⁶; andA¹, A², A³, A⁴, R², R³, R⁴, R⁵, p, q and r are as defined above.

R¹ is preferably a group of formula -A¹-(A²)_(q)-(A³)_(q)-(A⁴)_(r)-R⁶,or

wherein A¹, A², A³ and A⁴ are independently of each other a group offormula

whereinm5 is 0, or an integer of 1 to 4,m2 is 0, or an integer 1 to 3,X³ is —O—, —S—, or —NR¹⁵—,R⁷ and R⁸ are a C₁-C₁₈alkyl group,R¹⁵ is a C₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which is interruptedby —O—; a C₆-C₁₈aryl group; a C₆-C₁₈aryl group, which is substituted byone, or more C₁-C₁₈alkyl, or C₁-C₁₈alkoxy groups; a C₂-C₂₀heteroarylgroup, or a C₂-C₂₀heteroaryl group, which is substituted by one, or moreC₁-C₁₈alkyl groups, andR⁴¹ may be the same, or different in each occurrence and is F,C₁-C₁₈alkyl, C₁-C₁₈alkyl which is substituted by E and/or interrupted byD, C₆-C₂₄aryl, C₆-C₂₄aryl which is substituted by G, C₂-C₂₀heteroaryl,or C₂-C₂₀heteroaryl which is substituted by G.

R⁶ is preferably a group of formula

R⁴³ may be the same, or different in each occurrence and is F,C₁-C₁₈alkyl, C₁-C₁₈alkyl which is substituted by E and/or interrupted byD, C₆-C₂₄aryl, C₆-C₂₄aryl which is substituted by G, C₂-C₂₀heteroaryl,or C₂-C₂₀heteroaryl which is substituted by G, m3 is 0, or an integer of1 to 4. E, D, G, R¹¹, R¹², R¹³ and R¹⁴ are as defined above.R², R³, R⁴ and R⁵ are preferably hydrogen.

Preferably, A¹, A², A³ and A⁴ are independently of each other a group offormula

wherein R¹⁵ is a C₆-C₁₈aryl group; or a C₆-C₁₈aryl group, which issubstituted by one, or more C₁-C₁₈alkyl groups.R¹⁵ is preferably a group of formula

wherein R¹⁰⁰ is a C₁-C₈alkyl group.R⁶ is a group of formula

especially a group of formula

R², R³, R⁴, R⁵, R¹¹, R¹², R¹³, R¹⁴, R⁴³ and m3 are as defined above.In said embodiment the group of formula-A¹-(A²)_(p)-(A³)_(q)-(A⁴)_(r)-is especially a group of formula (IVa),(IVb), (IVc), (IVd), (IVe), (IVf), (IVg), (IVh), (IVi), (IVj), (IVk),(IVl), (IVm), (IVn), (IVo), (IVp),

(IVq), (IVr), (IVs), (IVt), (IVu), (IVv), (IVw), (IVx), (IVy), (IVz),(VIa), (VIb), (VIc), (VId), (VIe), (VIf), (VIg), (VIh), (VIi), (VIj),(VIk), (VIl), (VIm), (VIn), (VIo), (VIp), (VIq), (VIr), (VIs), (VIt), or(VIu). The at present most preferred groups of formula-A¹-(A²)_(p)-(A³)_(q)-(A⁴)_(r)-are the groups of formula (IVa), (IVb),(IVe), (IVl), (IVk), (IVs), (IVv) and (VIj).

Examples of preferred compounds are compounds D-1 to D-144, E-1 to E-183as well as H-1 to H-264 shown in the tables below.

Cpd. L¹ ³⁾ R⁶ D-1

D-2

D-3

D-4

D-5

D-6

D-7

D-8

D-9

D-10

D-11

D-12

D-13

D-14

D-15

D-16

D-17

D-18

D-19

D-20

D-21

D-22

D-23

D-24

D-25

D-26

D-27

D-28

D-29

D-30

D-31

D-32

D-33

D-34

D-35

D-36

D-37

D-38

D-39

D-40

D-41

D-42

D-43

D-44

D-45

D-46

D-47

D-48

D-49

D-50

D-51

D-52

D-53

D-55

D-56

D-57

D-58

D-59

D-60

D-61

D-62

D-63

D-64

D-65

D-66

D-67

D-68

D-69

D-70

D-71

D-72

D-73

D-74

D-75

D-76

D-77

D-78

D-79

D-80

D-81

D-82

D-83

D-84

D-85

D-86

D-87

D-88

D-89

D-90

D-91

D-92

D-93

D-94

D-95

D-96

D-97

D-98

D-99

D-100

D-101

D-102

D-103

D-104

D-105

D-106

D-107

D-108

D-109

D-110

D-111

D-112

D-113

D-114

D-115

D-116

D-117

D-118

D-119

D-120

D-121

D-122

D-123

D-124

D-125

D-126

D-127

D-128

D-129

D-130

D-131

D-132

D-133

D-134

D-135

D-136

D-137

D-138

D-139

D-140

D-141

D-142

D-143

D144

CpE. L¹ ³⁾ R⁶ E-1

E-2

E-3

E-4

E-5

E-6

E-7

E-8

E-9

E-10

E-11

E-12

E-13

E-14

E-15

E-16

E-17

E-18

E-19

E-20

E-21

E-22

E-23

E-24

E-25

E-26

E-27

E-28

E-29

E-30

E-31

E-32

E-33

E-34

E-35

E-36

E-37

E-38

E-39

E-40

E-41

E-42

E-43

E-44

E-45

E-46

E-47

E-48

E-49

E-50

E-51

E-52

E-53

E-55

E-56

E-57

E-58

E-59

E-60

E-61

E-62

E-63

E-64

E-65

E-66

E-67

E-68

E-69

E-70

E-71

E-72

E-73

E-74

E-75

E-76

E-77

E-78

E-79

E-80

E-81

E-82

E-83

E-84

E-85

E-86

E-87

E-88

E-89

E-90

E-91

E-92

E-93

E-94

E-95

E-96

E-97

E-98

E-99

E-100

E-101

E-102

E-103

E-104

E-105

E-106

E-107

E-108

E-109

E-110

E-111

E-112

E-113

E-114

E-115

E-116

E-117

E-118

E-119

E-120

E-121

E-122

E-123

E-124

E-125

E-126

E-127

E-128

E-129

E-130

E-131

E-132

E-133

E-134

E-135

E-136

E-137

E-138

E-139

E-140

E-141

E-142

E-143

E-144

E-145

E-146

E-147

E-148

E-149

E-150

E-151

E-152

E-153

E-154

E-155

E-156

E-157

E-158

E-159

E-160

E-161

E-162

E-163

E-164

E-165

E-166

E-167

E-168

E-169

E-170

E-171

E-172

E-173

E-174

E-175

E-176

E-177

E-178

E-179

E-180

E-181

E-182

E-183

Cpd. L¹⁴⁾ R⁶ H-1

H-2

H-3

H-4

H-5

H-6

H-3

H-4

H-5

H-6

H-7

H-8

H-9

H-10

H-11

H-12

H-13

H-14

H-15

H-16

H-17

H-18

H-19

H-20

H-21

H-22

H-23

H-24

H-25

H-26

H-27

H-28

H-29

H-30

H-31

H-32

H-33

H-34

H-35

H-36

H-27

H-38

H-39

H-40

H-41

H-42

H-43

H-44

H-45

H-46

H-47

H-48

H-49

H-50

H-51

H-52

H-53

H-54

H-55

H-56

H-57

H-58

H-59

H-60

H-61

H-62

H-63

H-64

H-67

H-68

H-69

H-70

H-71

H-72

H-73

H-74

H-75

H-76

H-77

H-78

H-79

H-80

H-81

H-82

H-83

H-84

H-85

H-86

H-87

H-88

H-89

H-90

H-91

H-92

H-93

H-94

H-95

H-96

H-97

H-98

H-99

H-100

H-101

H-102

H-103

H-104

H-105

H-106

H-107

H-108

H-109

H-110

H-111

H-112

H-113

H-114

H-115

H-116

H-117

H-118

H-119

H-120

H-121

H-122

H-123

H-124

H-125

H-126

H-127

H-128

H-129

H-130

H-131

H-132

H-133

H-134

H-135

H-136

H-137

H-138

H-139

H-140

H-141

H-142

H-143

H-144

H-145

H-146

H-147

H-148

H-149

H-150

H-151

H-152

H-153

H-154

H-155

H-156

H-157

H-158

H-159

H-160

H-161

H-162

H-163

H-164

H-165

H-166

H-167

H-168

H-169

H-170

H-171

H-172

H-173

H-174

H-175

H-176

H-177

H-178

H-179

H-180

H-181

H-182

H-183

H-184

H-185

H-186

H-187

H-188

H-189

H-190

H-191

H-192

H-193

H-194

H-195

H-196

H-196

H-197

H-198

H-199

H-200

H-201

H-202

H-203

H-204

H-205

H-206

H-207

H-208

H-209

H-210

H-211

H-212

H-213

H-214

H-215

H-216

H-217

H-218

H-219

H-220

H-221

H-222

H-223

H-224

H-225

H-226

H-227

H-228

H-229

H-230

H-231

H-232

H-232

H-233

H-234

H-235

H-236

H-237

H-238

H-239

H-240

H-241

H-242

H-243

H-244

H-245

H-246

H-247

H-248

H-249

H-250

H-251

H-251

H-252

H-253

H-254

H-255

H-256

H-257

H-258

H-259

H-260

H-261

H-262

H-263

H-264

In another preferred embodiment the present invention is directed tocompounds of formula

wherein R¹ is a group of formula -A¹-(A²)_(p)-(A³)_(q)-A⁴-R⁶; whereinA¹, A² and A³ are independently of each other a group of formula

wherein R¹⁵ is a C₆-C₁₈ aryl group; or a C₆-C₁₈ aryl group, which issubstituted by one, or more C₁-C₁₈alkyl groups,

A⁴ is a group of formula

which is bonded to A³ via the N-atom;R⁶ is a group of formula

and p and q are as defined above.

R¹⁵ is preferably a group of formula

wherein R¹⁰⁰ is a C₁-C₈alkyl group. In said embodiment the group offormula -A¹-(A²)_(p)-(A³)_(q)-is especially a group of formula (IVa),(IVb), (IVc), (IVd), (IVe), (IVf), (IVg), (IVi), (IVj), (IVk), (IVl),(IVm), (IVn), (IVo), (IVp), (IVq), (IVr), (IVs), (IVt), (IVu), (IVv),(IVw), (IVx), (IVy), (IVz), (VIa), (VIb), (VIc), (VId), (VIe), (VIf),(VIg), (VIh), (VIi), (VIj), (VIk), (VIl), (VIm), (VIn), (VIo), (VIp),(VIq), (VIr), (VIs), (VIt), or (VIu). The at present most preferredgroups of formula -A¹-(A²)_(p)-(A³)_(q)-are the groups of formula (IVa),(IVb), (IVe), (IVl), (IVk), (IVs), (IVv) and (VIj).

In case the compounds of formula I are used as host material for blue,or green phosphorescent emitters, or as electron/exciton blockingmaterial, groups A¹-(A²)_(p)-(A³)_(q)-(A⁴)_(r) are

less preferred, which contain a group of formula i.e. groups of formula(IVp) and (IVr). Examples of preferred compounds are compounds F-1 toF-62 as well as G-1 to G-62 shown in the tables below.

Cpd. L² ²⁾ F-1

F-2

F-3

F-4

F-5

F-6

F-7

F-8

F-9

F-10

F-11

F-12

F-13

F-14

F-15

F-16

F-17

F-18

F-19

F-20

F-21

F-22

F-23

F-24

F-25

F-26

F-27

F-28

F-29

F-30

F-31

F-32

F-33

F-34

F-35

F-36

F-37

F-38

F-39

F-40

F-41

F-42

F-43

F-44

F-45

F-46

F-47

F-48

F-49

F-50

F-51

F-52

F-53

F-54

F-55

F-56

F-57

F-58

F-59

F-60

F-61

F-62

Cpd. L² ²⁾ G-1

G-2

G-3

G-4

G-5

G-6

G-7

G-8

G-9

G-10

G-11

G-12

G-13

G-14

G-15

G-16

G-17

G-18

G-19

G-20

G-21

G-22

G-23

G-24

G-25

G-26

G-27

G-28

G-29

G-30

G-31

G-32

G-33

G-34

G-35

G-36

G-37

G-38

G-39

G-40

G-41

G-42

G-43

G-44

G-45

G-46

G-47

G-48

G-49

G-50

G-51

G-52

G-53

G-54

G-55

G-56

G-57

G-58

G-59

G-60

G-61

G-62

In the above tables the references ¹⁾, ²⁾, ³⁾ and ⁴⁾ have the followingmeaning:

²⁾ The dotted line indicates the bond to the group of formula

³⁾ The dotted line indicates the bond to the groups of formula

respectively.

⁴⁾ The dotted line indicates the bond to the group of formula

In another preferred embodiment the present invention is directed tocompounds M-1 to M-62, which result from compounds F-1 to F-62 byreplacing the group of formula

by a group of formula

In another preferred embodiment the present invention is directed tocompounds N-1 to N-62, which result from compounds F-1 to F-62 byreplacing the group of formula

by a group of formula

In another preferred embodiment the present invention is directed tocompounds O-1 to O-62, which result from compounds F-1 to F-62 byreplacing the group of formula

by a group of formula

In another preferred embodiment the present invention is directed tocompounds P-1 to P-62, which result from compounds G-1 to G-62 byreplacing the group of formula

by a group of formula

In another preferred embodiment the present invention is directed tocompounds Q-1 to Q-62, which result from compounds G-1 to G-62 byreplacing the group of formula

by a group of formula

In another preferred embodiment the present invention is directed tocompounds R-1 to R-62, which result from compounds G-1 to G-62 byreplacing the group of formula

by a group of formula

The at present most preferred compounds are compounds

In particular, compounds containing imidazole moieties of formula

are found to be suitable for use in organo-electroluminescent devices.

Halogen is fluorine, chlorine, bromine and iodine.

C₁-C₂₅alkyl (C₁-C₁₈alkyl) is typically linear or branched, wherepossible. Examples are methyl, ethyl, n-propyl, isopropyl, n-butyl,sec.-butyl, isobutyl, tert.-butyl, n-pentyl, 2-pentyl, 3-pentyl,2,2-dimethylpropyl, 1,1,3,3-tetramethylpentyl, n-hexyl, 1-methylhexyl,1,1,3,3,5,5-hexamethylhexyl, n-heptyl, isoheptyl,1,1,3,3-tetramethylbutyl, 1-methylheptyl, 3-methylheptyl, n-octyl,1,1,3,3-tetramethylbutyl and 2-ethylhexyl, n-nonyl, decyl, undecyl,dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, oroctadecyl. C₁-C₈alkyl is typically methyl, ethyl, n-propyl, isopropyl,n-butyl, sec.-butyl, isobutyl, tert.-butyl, n-pentyl, 2-pentyl,3-pentyl, 2,2-dimethyl-propyl, n-hexyl, n-heptyl, n-octyl,1,1,3,3-tetramethylbutyl and 2-ethylhexyl. C₁-C₄alkyl is typicallymethyl, ethyl, n-propyl, isopropyl, n-butyl, sec.-butyl, isobutyl,tert.-butyl.

C₁-C₂₅alkoxy groups (C₁-C₁₈alkoxy groups) are straight-chain or branchedalkoxy groups, e.g. methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy,sec-butoxy, tert-butoxy, amyloxy, isoamyloxy or tert-amyloxy, heptyloxy,octyloxy, isooctyloxy, nonyloxy, decyloxy, undecyloxy, dodecyloxy,tetradecyloxy, pentadecyloxy, hexadecyloxy, heptadecyloxy andoctadecyloxy. Examples of C₁-C₈alkoxy are methoxy, ethoxy, n-propoxy,isopropoxy, n-butoxy, sec.-butoxy, isobutoxy, tert.-butoxy, n-pentyloxy,2-pentyloxy, 3-pentyloxy, 2,2-dimethylpropoxy, n-hexyloxy, n-heptyloxy,n-octyloxy, 1,1,3,3-tetramethylbutoxy and 2-ethylhexyloxy, preferablyC₁-C₄alkoxy such as typically methoxy, ethoxy, n-propoxy, isopropoxy,n-butoxy, sec.-butoxy, isobutoxy, tert.-butoxy.

The term “cycloalkyl group” is typically C₄-C₁₈cycloalkyl, especiallyC₅-C₁₂cycloalkyl, such as cyclopentyl, cyclohexyl, cycloheptyl,cyclooctyl, cyclononyl, cyclodecyl, cycloundecyl, cyclododecyl,preferably cyclopentyl, cyclohexyl, cycloheptyl, or cyclooctyl, whichmay be unsubstituted or substituted.

C₆-C₂₄aryl (C₆-C₁₈aryl), which optionally can be substituted, istypically phenyl, 4-methylphenyl, 4-methoxyphenyl, naphthyl, especially1-naphthyl, or 2-naphthyl, biphenylyl, terphenylyl, pyrenyl, 2- or9-fluorenyl, phenanthryl, or anthryl, which may be unsubstituted orsubstituted.

C₂-C₃₀heteroaryl represents a ring with five to seven ring atoms or acondensed ring system, wherein nitrogen, oxygen or sulfur are thepossible hetero atoms, and is typically a heterocyclic group with fiveto 30 atoms having at least six conjugated π-electrons such as thienyl,benzothiophenyl, dibenzothiophenyl, thianthrenyl, furyl, furfuryl,2H-pyranyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl,phenoxythienyl, pyrrolyl, imidazolyl, pyrazolyl, pyridyl, bipyridyl,triazinyl, pyrimidinyl, pyrazinyl, pyridazinyl, indolizinyl, isoindolyl,indolyl, indazolyl, purinyl, quinolizinyl, chinolyl, isochinolyl,phthalazinyl, naphthyridinyl, chinoxalinyl, chinazolinyl, cinnolinyl,pteridinyl, carbazolyl, carbolinyl, benzotriazolyl, benzoxazolyl,phenanthridinyl, acridinyl, pyrimidinyl, phenanthrolinyl, phenazinyl,isothiazolyl, phenothiazinyl, isoxazolyl, furazanyl,4-imidazo[1,2-a]benzimidazoyl, 5-benzimidazo[1,2-a]benzimidazoyl,carbazolyl, or phenoxazinyl, which can be unsubstituted or substituted.

The C₆-C₂₄aryl (C₆-C₁₈aryl) and C₂-C₃₀heteroaryl groups are preferablysubstituted by one, or more C₁-C₈alkyl groups.

The term “aryl ether group” is typically a C₆₋₂₄aryloxy group, that isto say O—C₆₋₂₄aryl, such as, for example, phenoxy or 4-methoxyphenyl.

Possible substituents of the above-mentioned groups are C₁-C₈alkyl, ahydroxyl group, a mercapto group, C₁-C₈alkoxy, C₁-C₈alkylthio, halogen,halo-C₁-C₈alkyl, or a cyano group.

If a substituent, such as, for example R⁴¹ occurs more than one time ina group, it can be different in each occurrence.

The wording “substituted by G” means that one, or more, especially oneto three substituents G might be present.

As described above, the aforementioned groups may be substituted by Eand/or, if desired, interrupted by D. Interruptions are of coursepossible only in the case of groups containing at least 2 carbon atomsconnected to one another by single bonds; C₆-C₁₈aryl is not interrupted;interrupted arylalkyl contains the unit D in the alkyl moiety.C₁-C₁₈alkyl substituted by one or more E and/or interrupted by one ormore units D is, for example, (CH₂CH₂O)₁₋₉—R^(x), where R^(x) is H orC₁-C₁₀alkyl or C₂-C₁₀alkanoyl (e.g. CO—CH(C₂H₅)C₄H₉),CH₂—CH(OR^(y′))—CH₂—O—R^(y), where R^(y) is C₁-C₁₈alkyl,C₅-C₁₂cycloalkyl, phenyl, C₇-C₁₅phenylalkyl, and R^(y′) embraces thesame definitions as R^(y) or is H;

C₁-C₈alkylene-COO—R^(z), e.g. CH₂COOR^(z), CH(CH₃)COOR^(z),C(CH₃)₂COOR^(z), where R^(z) is H, C₁-C₁₈alkyl, (CH₂CH₂O)₁₋₉—R^(x), andR^(x) embraces the definitions indicated above; CH₂CH₂—O—CO—CH═CH₂;CH₂CH(OH)CH₂—O—CO—C(CH₃)═CH₂.

The synthesis of

is described, for example, in Achour, Reddouane; Zniber, Rachid,Bulletin des Societes Chimiques Beiges 96 (1987) 787-92.

Suitable base skeletons of the formula

are either commercially available (especially in the cases when X is S,O, NH), or can be obtained by processes known to those skilled in theart. Reference is made to WO2010079051 and EP1885818.

The halogenation can be performed by methods known to those skilled inthe art. Preference is given to brominating or iodinating in the 3 and 6positions (dibromination) or in the 3 or 6 positions (monobromination)of the base skeleton of the formula (II) 2,8 positions (dibenzofuran anddibenzothiophene) or 3,6 positions (carbazole).

Optionally substituted dibenzofurans, dibenzothiophenes and carbazolescan be dibrominated in the 2,8 positions (dibenzofuran anddibenzothiophene) or 3,6 positions (carbazole) with bromine or NBS inglacial acetic acid or in chloroform. For example, the bromination withBr2 can be effected in glacial acetic acid or chloroform at lowtemperatures, e.g. 0° C. Suitable processes are described, for example,in M. Park, J. R. Buck, C. J. Rizzo, Tetrahedron, 54 (1998) 12707-12714for X═NPh, and in W. Yang et al., J. Mater. Chem. 13 (2003) 1351 forX═S. In addition, 3,6-dibromocarbazole, 3,6-dibromo-9-phenylcarbazole,2,8-dibromodibenzothiophene, 2,8-dibromodibenzofuran, 2-bromocarbazole,3-bromodibenzothiophene, 3-bromodibenzofuran, 3-bromocarbazole,2-bromodibenzothiophene and 2-bromodibenzofuran are commerciallyavailable.

Monobromination in the 4 position of dibenzofuran (and analogously fordibenzothiophene) is described, for example, in J. Am. Chem. Soc. 1984,106, 7150. Dibenzofuran (dibenzothiophene) can be monobrominated in the3 position by a sequence known to those skilled in the art, comprising anitration, reduction and subsequent Sandmeyer reaction.

Monobromination in the 2 position of dibenzofuran or dibenzothiopheneand monobromination in the 3 position of carbazole are effectedanalogously to the dibromination, with the exception that only oneequivalent of bromine or NBS is added.

Alternatively, it is also possible to utilize iodinated dibenzofurans,dibenzothiophenes and carbazoles. The preparation is described, interalia, in Tetrahedron. Lett. 47 (2006) 6957-6960, Eur. J. Inorg. Chem. 24(2005) 4976-4984, J. Heterocyclic Chem. 39 (2002) 933-941, J. Am. Chem.Soc. 124 (2002) 11900-11907, J. Heterocyclic Chem, 38 (2001) 77-87.

For the nucleophilic substitution, Cl- or F-substituted dibenzofurans,dibenzothiophenes and carbazoles are required. The chlorination isdescribed, inter alia, in J. Heterocyclic Chemistry, 34 (1997) 891-900,Org. Lett., 6 (2004) 3501-3504; J. Chem. Soc. [Section] C: Organic, 16(1971) 2775-7, Tetrahedron Lett. 25 (1984) 5363-6, J. Org. Chem. 69(2004) 8177-8182. The fluorination is described in J. Org. Chem. 63(1998) 878-880 and J. Chem. Soc., Perkin Trans. 2, 5 (2002) 953-957.

The introduction of the group

is performed in the presence of a base. Suitable bases are known tothose skilled in the art and are preferably selected from the groupconsisting of alkali metal and alkaline earth metal hydroxides such asNaOH, KOH, Ca(OH)₂, alkali metal hydrides such as NaH, KH, alkali metalamides such as NaNH₂, alkali metal or alkaline earth metal carbonatessuch as K₂CO₃ or Cs₂CO₃, and alkali metal alkoxides such as NaOMe,NaOEt. In addition, mixtures of the aforementioned bases are suitable.Particular preference is given to NaOH, KOH, NaH or K₂CO₃.

Heteroarylation can be effected, for example, by copper-catalyzedcoupling of

to a halogenated compound of the formula

(Ullmann reaction).

The N-arylation was, for example, disclosed in H. Gilman and D. A.Shirley, J. Am. Chem. Soc. 66 (1944) 888; D. Li et al., Dyes andPigments 49 (2001) 181-186 and Eur. J. Org. Chem. (2007) 2147-2151. Thereaction can be performed in solvent or in a melt. Suitable solventsare, for example, (polar) aprotic solvents such as dimethyl sulfoxide,dimethylformamide, NMP, tridecane or alcohols.

The synthesis of 9-(8-bromodibenzofuran-2-yl)carbazole,

is described in WO2010079051. The synthesis of2-bromo-8-iodo-dibenzofurane,

is described in EP1885818.

A possible synthesis route for the compound of formula

is shown in the following scheme:

Reference is made to Angew. Chem. Int. Ed. 46 (2007) 1627-1629.

Diboronic acid or diboronate group containing dibenzofurans,dibenzothiophenes and carbazoles can be readily prepared by anincreasing number of routes. An overview of the synthetic routes is, forexample, given in Angew. Chem. Int. Ed. 48 (2009) 9240-9261.

By one common route diboronic acid or diboronate group containingdibenzofurans, dibenzothiophenes, and carbazoles can be obtained byreacting halogenated dibenzofurans, dibenzothiophenes and carbazoleswith (Y¹O)₂B—B(OY¹)₂,

in the presence of a catalyst, such as, for example,[1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II), complex(Pd(Cl)₂(dppf)), and a base, such as, for example, potassium acetate, ina solvent, such as, for example, dimethyl formamide, dimethyl sulfoxide,dioxane and/or toluene (cf. Prasad Appukkuttan et al., Synlett 8 (2003)1204), wherein Y¹ is independently in each occurrence a C₁-C₁₈alkylgroupand Y² is independently in each occurrence a C₂-C₁₀alkylene group, suchas —CY³Y⁴—CY⁵Y⁶—, or —CY⁷Y⁸—CY⁹Y¹⁰—CY¹¹Y¹²—, wherein Y³, Y⁴, Y⁵, Y⁶, Y⁷,Y⁶, Y⁷, Y¹⁰, Y¹¹ and Y¹² are independently of each other hydrogen, or aC₁-C₁₈alkylgroup, especially —C(CH₃)₂C(CH₃)₂—, —C(CH₃)₂CH₂C(CH₃)₂—, or—CH₂C(CH₃)₂CH₂—, and Y¹³ and Y¹⁴ are independently of each otherhydrogen, or a C₁-C₁₈alkylgroup.

Diboronic acid or diboronate group containing dibenzofurans,dibenzothiophenes and carbazoles can also be prepared by reactinghalogenated dibenzofurans, dibenzothiophenes and carbazoles with alkyllithium reagents, such as, for example, n-butyl lithium, or t-buthyllithium, followed by reaction with boronic esters, such as, for example,B(isopropoxy)₃, B(methoxy)₃, or

Diboronic acid or diboronate group containing dibenzofurans,dibenzothiophenes and carbazoles can also be prepared by reactingdibenzofurans, dibenzothiophenes and carbazoles with lithium amides,such as, for example, lithium diisopropylamide (LDA) followed byreaction with boronic esters such as, for example, B(isopropoxy)₃,B(methoxy)₃, or

Diboronic acid or diboronate group containing dibenzofurans,dibenzothiophenes and carbazoles, such as, for example,

can be reacted with equimolar amounts of halogenated dibenzofurans,dibenzothiophenes and carbazoles, such as, for example,

in a solvent and in the presence of a catalyst. The catalyst may be oneof the μ-halo(triisopropylphosphine)(η³-allyl)palladium(II) type (seefor example WO99/47474).

Preferably, the Suzuki reaction is carried out in the presence of anorganic solvent, such as an aromatic hydrocarbon or a usual polarorganic solvent, such as benzene, toluene, xylene, tetrahydrofurane, ordioxane, or mixtures thereof, most preferred toluene. Usually, theamount of the solvent is chosen in the range of from 1 to 10 l per molof boronic acid derivative. Also preferred, the reaction is carried outunder an inert atmosphere such as nitrogen, or argon. Further, it ispreferred to carry out the reaction in the presence of an aqueous base,such as an alkali metal hydroxide or carbonate such as NaOH, KOH,Na₂CO₃, K₂CO₃, Cs₂CO₃ and the like, preferably an aqueous K₂CO₃ solutionis chosen. Usually, the molar ratio of the base to boronic acid orboronic ester derivative is chosen in the range of from 0.5:1 to 50:1,very especially 1:1. Generally, the reaction temperature is chosen inthe range of from 40 to 180° C., preferably under reflux conditions.Preferred, the reaction time is chosen in the range of from 1 to 80hours, more preferably from 20 to 72 hours. In a preferred embodiment ausual catalyst for coupling reactions or for polycondensation reactionsis used, preferably Pd-based, which is described in WO2007/101820. Thepalladium compound is added in a ratio of from 1:10000 to 1:50,preferably from 1:5000 to 1:200, based on the number of bonds to beclosed. Preference is given, for example, to the use of palladium(II)salts such as PdAc₂ or Pd₂dba₃ and to the addition of ligands selectedfrom the group consisting of

wherein

The ligand is added in a ratio of from 1:1 to 1:10, based on Pd. Alsopreferred, the catalyst is added as in solution or suspension.Preferably, an appropriate organic solvent such as the ones describedabove, preferably benzene, toluene, xylene, THF, dioxane, morepreferably toluene, or mixtures thereof, is used. The amount of solventusually is chosen in the range of from 1 to 10 l per mol of boronic acidderivative. Organic bases, such as, for example, tetraalkylammoniumhydroxide, and phase transfer catalysts, such as, for example TBAB, canpromote the activity of the boron (see, for example, Lead-beater &Marco; Angew. Chem. Int. Ed. Eng. 42 (2003) 1407 and references citedtherein). Other variations of reaction conditions are given by T. I.Wallow and B. M. Novak in J. Org. Chem. 59 (1994) 5034-5037; and M.Remmers, M. Schulze, G. Wegner in Macromol. Rapid Commun. 17 (1996)239-252 and G. A. Molander and B. Canturk, Angew. Chem., 121 (2009)9404-9425.

A possible synthetic route for compound A-1 is shown in the reactionscheme below:

A possible synthetic route for compound B-3 is shown in the reactionscheme below:

The halogen/metal exchange is done with nBuLi/THF at −78° C., ortBuLi/THF at −78° C. Reference is made to WO2010/079051, where thesynthesis of such compounds is described.

Compounds of formula

may also be synthesized by reacting a compound of formula

in the presence of a catalyst, such as, for example, copper acetate(Cu(OAc)₂); a ligand, such as, for example, PPh₃, and1,10-phenathroline; a base, such as, for example, sodium acetate(NaOAc), sodium carbonate, potassium carbonate, caesium carbonate,potassium phosphate, and sodium hydrogencarbonate; a solvent, such as,for example, o-, m- and p-xylene, and oxygen (1 atm) at elevatedtemperature, especially a temperature of 100 to 160° C. for 1 to 72 h.Reference is made to X. Wang et al. Org. Lett. 14 (2012) 452-455[published on web: Dec. 29, 2011].

The compounds of the formula

are intermediates in the production of the compounds of the presentinvention, are new and form a further subject of the present invention.X^(6′) is —N═ and X^(7′) is —NR^(1′)—, or X^(7′) is ═N— and X^(6′) is—NR^(1′)—, R^(1′) is a group of formula-A¹-(A²)_(p)-(A³)_(q)-(A⁴)_(r)-(R^(6′))_(t), t is 1, or 2, especially 1;p, q, r, A¹, A², A³, A⁴, X¹, X², R², R³, R⁴ and R⁵ are as defined above.

In one embodiment R^(6′) is halogen, especially Cl, Br, or J;—OS(O)₂CF₃, —OS(O)₂-aryl, especially

or —OS(O)₂CH₃; very especially Br, or J.In another embodiment R^(6′) is znx¹²; —SnR²⁰⁷R²⁰⁸R²⁰⁹, wherein R²⁰⁷,R²⁰⁸ and R²⁰⁹ are identical or different and are H or C₁-C₆alkyl,wherein two radicals optionally form a common ring and these radicalsare optionally branched or unbranched; and X¹² is a halogen atom,especially I, or Br; —B(OH)₂, —B(OY¹)₂,

—BF₄Na, or —BF₄K, wherein Y¹ is independently in each occurrence aC₁-C₁₀alkyl group and Y² is independently in each occurrence aC₂-C₁₀alkylene group, such as —CY³Y⁴—CY⁵Y⁶—, or —CY⁷Y⁸—CY⁹Y¹⁰—CY¹¹Y¹²—,wherein Y³, Y⁴, Y⁵, Y⁶, Y⁷, Y⁸, Y⁹, Y¹⁰, Y¹¹ and Y¹² are independentlyof each other hydrogen, or a C₁-C₁₀alkyl group, ly —C(CH₃)₂C(CH₃)₂—,—C(CH₃)₂CH₂C(CH₃)₂—, or —CH₂C(CH₃)₂CH₂—, and Y¹³ and Y¹⁴ areindependently of each other hydrogen, or a C₁-C₁₀alkyl group. Withrespect to p, q, r, A¹, A², A³, A⁴, X¹, X², R², R³, R⁴ and R⁵ the samepreferences apply as for the compounds of formula I. Examples of theintermediates are shown below:

The compounds of formula I can be obtained starting from theintermediates and suitable co-reactants, for example, by Suzuki-,Stille-, or Negishi-coupling reactions.

A process for the preparation of a compound of formula

wherein R², R³, R⁴, R⁵ R¹¹, R¹², R¹³ and R¹⁴ are H, and R¹ is as definedabove, may comprise (a) heating a compound of formula

in H₃PO₄, polyphosporic acid, CH₃SO₃H/P₂O₅, CH₃SO₃H, or sulfuric acid toobtain a compound of formula

and (b) reacting the compound of formula XI to a compound of formula II.Various examples for step b) are illustrated above. In step a) asolvent, or mixtures of solvents having a boiling point above 140° C.,such as, for example, xylene, or mesitylen, may be present. Compounds offormula X are stirred under an atmosphere of inert gas, such as, forexample, nitrogen, or argon, at a temperature above 140° C., preferablyabove 160° C., more preferably above 180° C., for a time of 30 minutesto 3 weeks, preferably 1 to 48 h.

It has been found that the compounds of the formula I are particularlysuitable for use in applications in which charge carrier conductivity isrequired, especially for use in organic electronics applications, forexample selected from switching elements such as organic transistors,e.g. organic FETs and organic TFTs, organic solar cells and organiclight-emitting diodes (OLEDs), the compounds of the formula I beingparticularly suitable in OLEDs for use as matrix material in alight-emitting layer and/or as hole and/or exciton blocker materialand/or as electron and/or exciton blocker material, especially incombination with a phosphorescence emitter. In the case of use of theinventive compounds of the formula I in OLEDs, OLEDs which have goodefficiencies and a long lifetime and which can be operated especially ata low use and operating voltage are obtained. The inventive compounds ofthe formula I are suitable especially for use as matrix and/orhole/exciton blocker materials for blue and green emitters, for examplelight blue or deep blue emitters, these being especially phosphorescenceemitters. Furthermore, the compounds of the formula I can be used asconductor/complementary materials in organic electronics applicationsselected from switching elements and organic solar cells.

The compounds of the formula I can be used as matrix material and/orhole/exciton blocker material and/or electron/exciton blocker materialand/or hole injection material and/or electron injection material and/orhole conductor material (hole transport material) and/or electronconductor material (electron transport material), preferably as matrixmaterial and/or electron/exciton blocker and/or hole transportingmaterial in organic electronics applications, especially in OLEDs. Theinventive compounds of the formula I are more preferably used as matrixmaterials in organic electronics applications, especially in OLEDs.

In the emission layer or one of the emission layers of an OLED, it isalso possible to combine an emitter material with a matrix material ofthe compound of the formula I and a further matrix material which has,for example, a good hole conductor (hole transport) property. Thisachieves a high quantum efficiency of this emission layer.

When a compound of the formula I is used as matrix material in anemission layer and additionally as hole/exciton blocker material and/orelectron/exciton blocker material, owing to the chemical identity orsimilarity of the materials, an improved interface between the emissionlayer and the adjacent hole/exciton blocker material and/orelectron/exciton blocker material is obtained, which can lead to adecrease in the voltage with equal luminance and to an extension of thelifetime of the OLED. Moreover, the use of the same material forhole/exciton blocker material and/or electron/exciton blocker materialand for the matrix of an emission layer allows the production process ofan OLED to be simplified, since the same source can be used for thevapor deposition process of the material of one of the compounds of theformula I.

Suitable structures of organic electronic devices are known to thoseskilled in the art and are specified below.

The organic transistor generally includes a semiconductor layer formedfrom an organic layer with hole transport capacity and/or electrontransport capacity; a gate electrode formed from a conductive layer; andan insulating layer introduced between the semiconductor layer and theconductive layer. A source electrode and a drain electrode are mountedon this arrangement in order thus to produce the transistor element. Inaddition, further layers known to those skilled in the art may bepresent in the organic transistor.

The organic solar cell (photoelectric conversion element) generallycomprises an organic layer present between two plate-type electrodesarranged in parallel. The organic layer may be configured on a comb-typeelectrode. There is no particular restriction regarding the site of theorganic layer and there is no particular restriction regarding thematerial of the electrodes. When, however, plate-type electrodesarranged in parallel are used, at least one electrode is preferablyformed from a transparent electrode, for example an ITO electrode or afluorine-doped tin oxide electrode. The organic layer is formed from twosublayers, i.e. a layer with p-type semiconductor properties or holetransport capacity, and a layer formed with n-type semiconductorproperties or electron transport capacity. In addition, it is possiblefor further layers known to those skilled in the art to be present inthe organic solar cell. The layer with hole transport capacity maycomprise the compounds of formula I.

It is likewise possible that the compounds of the formula I are presentboth in the light-emitting layer (preferably as matrix material) and inthe blocking layer for electrons (as electron/exciton blockers).

The present invention further provides an organic light-emitting diodecomprising an anode An and a cathode Ka and a light-emitting layer Earranged between the anode An and the cathode Ka, and if appropriate atleast one further layer selected from the group consisting of at leastone blocking layer for holes/excitons, at least one blocking layer forelectrons/excitons, at least one hole injection layer, at least one holeconductor layer, at least one electron injection layer and at least oneelectron conductor layer, wherein the at least one compound of theformula I is present in the light-emitting layer E and/or in at leastone of the further layers. The at least one compound of the formula I ispreferably present in the light-emitting layer and/or the blocking layerfor holes.

The present application further relates to a light-emitting layercomprising at least one compound of the formula I.

Structure of the Inventive OLED

The inventive organic light-emitting diode (OLED) thus generally has thefollowing structure:

an anode (An) and a cathode (Ka) and a light-emitting layer E arrangedbetween the anode (An) and the cathode (Ka).

The inventive OLED may, for example—in a preferred embodiment—be formedfrom the following layers:

1. Anode

2. Hole conductor layer

3. Light-emitting layer

4. Blocking layer for holes/excitons

5. Electron conductor layer

6. Cathode

Layer sequences different than the aforementioned structure are alsopossible, and are known to those skilled in the art. For example, it ispossible that the OLED does not have all of the layers mentioned; forexample, an OLED with layers (1) (anode), (3) (light-emitting layer) and(6) (cathode) is likewise suitable, in which case the functions of thelayers (2) (hole conductor layer) and (4) (blocking layer forholes/excitons) and (5) (electron conductor layer) are assumed by theadjacent layers. OLEDs which have layers (1), (2), (3) and (6), orlayers (1), (3), (4), (5) and (6), are likewise suitable. In addition,the OLEDs may have a blocking layer for electrons/excitons between thehole conductor layer (2) and the Light-emitting layer (3).

It is additionally possible that a plurality of the aforementionedfunctions (electron/exciton blocker, hole/exciton blocker, holeinjection, hole conduction, electron injection, electron conduction) arecombined in one layer and are assumed, for example, by a single materialpresent in this layer. For example, a material used in the holeconductor layer, in one embodiment, may simultaneously block excitonsand/or electrons.

Furthermore, the individual layers of the OLED among those specifiedabove may in turn be formed from two or more layers. For example, thehole conductor layer may be formed from a layer into which holes areinjected from the electrode, and a layer which transports the holes awayfrom the hole-injecting layer into the light-emitting layer. Theelectron conduction layer may likewise consist of a plurality of layers,for example a layer in which electrons are injected by the electrode,and a layer which receives electrons from the electron injection layerand transports them into the light-emitting layer. These layersmentioned are each selected according to factors such as energy level,thermal resistance and charge carrier mobility, and also energydifference of the layers specified with the organic layers or the metalelectrodes. The person skilled in the art is capable of selecting thestructure of the OLEDs such that it is matched optimally to the organiccompounds used as emitter substances in accordance with the invention.

In order to obtain particularly efficient OLEDs, for example, the HOMO(highest occupied molecular orbital) of the hole conductor layer shouldbe matched to the work function of the anode, and the LUMO (lowestunoccupied molecular orbital) of the electron conductor layer should bematched to the work function of the cathode, provided that theaforementioned layers are present in the inventive OLEDs.

The anode (1) is an electrode which provides positive charge carriers.It may be formed, for example, from materials which comprise a metal, amixture of various metals, a metal alloy, a metal oxide or a mixture ofvarious metal oxides. Alternatively, the anode may be a conductivepolymer. Suitable metals comprise metals and alloys of the metals of themain groups, transition metals and of the lanthanoids, especially themetals of groups Ib, IVa, Va and VIa of the periodic table of theelements, and the transition metals of group Villa. When the anode is tobe transparent, generally mixed metal oxides of groups IIb, IIIb and IVbof the periodic table of the elements (IUPAC version) are used, forexample indium tin oxide (ITO). It is likewise possible that the anode(1) comprises an organic material, for example polyaniline, asdescribed, for example, in Nature, Vol. 357, pages 477 to 479 (Jun. 11,1992). At least either the anode or the cathode should be at leastpartly transparent in order to be able to emit the light formed. Thematerial used for the anode (1) is preferably ITO.

Suitable hole conductor materials for layer (2) of the inventive OLEDsare disclosed, for example, in Kirk-Othmer Encyclopedia of ChemicalTechnology, 4th edition, Vol. 18, pages 837 to 860, 1996. Bothhole-transporting molecules and polymers can be used as the holetransport material. Hole-transporting molecules typically used areselected from the group consisting oftris[N-(1-naphthyl)-N-(phenylamino)]triphenylamine (1-NaphDATA),4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (α-NPD),N,N′-diphenyl-N,N′-bis(3-methylphenyl)-[1,1′-biphenyl]-4,4′-diamine(TPD), 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC),N,N′-bis(4-methylphenyl)-N,N′-bis(4-ethylphenyl)[1,1′-(3,3′-dimethyl)biphenyl]-4,4′-diamine(ETPD), tetrakis(3-methylphenyl)-N,N,N′,N′-2,5-phenylenediamine (PDA),α-phenyl-4-N,N-diphenylaminostyrene (TPS), p-(diethylamino)benzaldehydediphenylhydrazone (DEH), triphenylamine (TPA),bis[4-(N,N-diethylamino)-2-methylphenyl)(4-methylphenyl)methane (MPMP),1-phenyl-3-[p-(diethylamino)styryl]-5-[p-(diethylamino)phenyl]pyrazoline(PPR or DEASP), 1,2-trans-bis(9H-carbazol-9-yl)cyclobutane (DCZB),N,N,N′,N′-tetrakis(4-methylphenyl)-(1,1′-biphenyl)-4,4′-diamine (TTB),4,4′,4″-tris(N,N-diphenylamino)triphenylamine (TDTA),4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA),N,N′-bis(naphthalen-2-yl)-N,N′-bis(phenyl)benzidine (β—NPB),N,N′-bis(3-methylphenyl)-N,N′-bis(phenyl)-9,9-spirobifluorene(Spiro-TPD),N,N′-bis(naphthalen-1-yl)-N,N′-bis(phenyl)-9,9-spirobifluorene(Spiro-NPB),N,N′-bis(3-methylphenyl)-N,N′-bis(phenyl)-9,9-dimethylfluorene(DMFL-TPD), di[4-(N,N-ditolylamino)phenyl]cyclohexane,N,N′-bis(naphthalen-1-yl)-N,N′-bis(phenyl)-9,9-dimethylfluorene,N,N′-bis(naphthalen-1-yl)-N,N′-bis(phenyl)-2,2-dimethylbenzidine,N,N′-bis(naphthalen-1-yl)-N,N′-bis(phenyl)benzidine,N,N′-bis(3-methylphenyl)-N,N′-bis(phenyl)benzidine,2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ),4,4′,4″-tris(N-3-methylphenyl-N-phenylamino)triphenylamine,4,4′,4″-tris(N-(2-naphthyl)-N-phenyl-amino)triphenylamine,pyrazino[2,3-f][1,10]phenanthroline-2,3-dicarbonitrile (PPDN),N,N,N′,N′-tetrakis(4-methoxyphenyl)benzidine (MeO-TPD),2,7-bis[N,N-bis(4-methoxyphenyl)amino]-9,9-spirobifluorene(MeO-Spiro-TPD),2,2′-bis[N,N-bis(4-methoxyphenyl)amino]-9,9-spirobifluorene(2,2′-MeO-Spiro-TPD),N,N′-diphenyl-N,N′-di[4-(N,N-ditolylamino)phenyl]benzidine (NTNPB),N,N′-diphenyl-N,N′-di[4-(N,N-diphenylamino)phenyl]benzidine (NPNPB),N,N′-di(naphthalen-2-yl)-N,N′-diphenylbenzene-1,4-diamine (β-NPP),N,N′-bis(3-methylphenyl)-N,N′-bis(phenyl)-9,9-diphenylfluorene(DPFL-TPD),N,N′-bis(naphthalen-1-yl)-N,N′-bis(phenyl)-9,9-diphenylfluorene(DPFL-NPB), 2,2′,7,7′-tetrakis(N,N-diphenylamino)-9,9′-spirobifluorene(Spiro-TAD), 9,9-bis[4-(N,N-bis(biphenyl-4-yl)amino)phenyl]-9H-fluorene(BPAPF), 9,9-bis[4-(N,N-bis(naphthalen-2-yl)amino)phenyl]-9H-fluorene(NPAPF),9,9-bis[4-(N,N-bis(naphthalen-2-yl)-N,N′-bisphenylamino)phenyl]-9H-fluorene(NPBAPF),2,2′,7,7′-tetrakis[Nnaphthalenyl(phenyl)amino]-9,9′-spirobifluorene(Spiro-2NPB), N,N′-bis(phenanthren-9-yl)-N,N′-bis(phenyl)benzidine(PAPB),2,7-bis[N,N-bis(9,9-spirobifluoren-2-yl)amino]-9,9-spirobifluorene(Spiro-5), 2,2′-bis[N,N-bis(biphenyl-4-yl)amino]-9,9-spirobifluorene(2,2′-Spiro-DBP), 2,2′-bis(N,N-diphenylamino)-9.9-spirobifluorene(Spiro-BPA), 2,2′,7,7′-tetra(N,N-ditolyl)aminospirobifluorene(Spiro-TTB), N,N,N′,N′-tetranaphthalen-2-ylbenzidine (TNB), porphyrincompounds and phthalocyanines such as copper phthalocyanines andtitanium oxide phthalocyanines. Hole-transporting polymers typicallyused are selected from the group consisting of polyvinylcarbazoles,(phenylmethyl)polysilanes and polyanilines. It is likewise possible toobtain hole-transporting polymers by doping hole-transporting moleculesinto polymers such as polystyrene and polycarbonate. Suitablehole-transporting molecules are the molecules already mentioned above.In addition—in one embodiment—it is possible to use carbene complexes ashole conductor materials, the band gap of the at least one holeconductor material generally being greater than the band gap of theemitter material used. In the context of the present application, “bandgap” is understood to mean the triplet energy. Suitable carbenecomplexes are, for example, carbene complexes as described in WO2005/019373 A2, WO 2006/056418 A2, WO 2005/113704, WO 2007/115970, WO2007/115981 and WO 2008/000727. One example of a suitable carbenecomplex is Ir(dpbic)₃ with the formula:

which is disclosed, for example, in WO2005/019373. In principle, it ispossible that the hole conductor layer comprises at least one compoundof the formula I as hole conductor material.

The light-emitting layer (3) comprises at least one emitter material. Inprinciple, it may be a fluorescence or phosphorescence emitter, suitableemitter materials being known to those skilled in the art. The at leastone emitter material is preferably a phosphorescence emitter. Thephosphorescence emitter compounds used with preference are based onmetal complexes, and especially the complexes of the metals Ru, Rh, Ir,Pd and Pt, in particular the complexes of Ir, have gained significance.The compounds of the formula I can be used as the matrix in thelight-emitting layer.

Suitable metal complexes for use in the inventive OLEDs are described,for example, in documents WO 02/60910 A¹, US 2001/0015432 A¹, US2001/0019782 A1, US 2002/0055014 A¹, US 2002/0024293 A¹, US 2002/0048689A¹, EP 1 191 612 A2, EP 1 191 613 A2, EP 1 211 257 A2, US 2002/0094453A¹, WO 02/02714 A2, WO 00/70655 A2, WO 01/41512 A¹, WO 02/15645 A¹, WO2005/019373 A2, WO 2005/113704 A2, WO 2006/115301 A¹, WO 2006/067074 A¹,WO 2006/056418, WO 2006121811 A¹, WO 2007095118 A2, WO 2007/115970, WO2007/115981, WO 2008/000727, WO2010129323, WO2010056669 and WO10086089.

Further suitable metal complexes are the commercially available metalcomplexes tris(2-phenylpyridine)iridium(III), iridium(III)tris(2-(4-tolyl)pyridinato-N,C^(2′)),bis(2-phenylpyridine)(acetylacetonato)iridium(III), iridium(III)tris(1-phenylisoquinoline), iridium(III)bis(2,2′-benzothienyl)pyridinato-N,C^(3′))(acetylacetonate),tris(2-phenylquinoline)iridium(III), iridium(III)bis(2-(4,6-difluorophenyl)pyridinato-N,C²)picolinate, iridium(III)bis(1-phenylisoquinoline)(acetylacetonate),bis(2-phenylquinoline)(acetylacetonato)iridium(III), iridium(III)bis(di-benzo[f,h]quinoxaline)(acetylacetonate), iridium(III)bis(2-methyldibenzo[f,h]quinoxaline)(acetylacetonate) andtris(3-methyl-1-phenyl-4-trimethylacetyl-5-pyrazolino)terbium(III),bis[1-(9,9-dimethyl-9H-fluoren-2-yl)isoquinoline](acetylacetonato)iridium(III),bis(2-phenylbenzothiazolato)(acetylacetonato)iridium(III),bis(2-(9,9-dihexylfluorenyl)-1-pyridine)(acetylacetonato)iridium(III),bis(2-benzo[b]thiophen-2-ylpyridine)(acetylacetonato)iridium(III).

In addition, the following commercially available materials aresuitable: tris(dibenzoylacetonato)mono(phenanthroline)europium(III),tris(dibenzoylmethane)mono(phenanthroline)europium(III),tris(dibenzoylmethane)mono(5-aminophenanthroline)europium(III),tris(di-2-naphthoylmethane)mono(phenanthroline)europium(III),tris(4-bromobenzoylmethane)mono(phenanthroline)europium(III),tris(di(biphenyl)methane)mono(phenanthroline)europium(III),tris(dibenzoylmethane)mono(4,7-diphenylphenanthroline)europium(III),tris(dibenzoylmethane)mono(4,7-di-methylphenanthroline)europium(III),tris(dibenzoylmethane)mono(4,7-dimethylphenanthrolinedisulfonicacid)europium(III) disodium salt,tris[di(4-(2-(2-ethoxyethoxy)ethoxy)benzoylmethane)]mono(phenanthroline)europium(III)andtris[di(4-(2-(2-ethoxyethoxy)ethoxy)benzoylmethaneAmono(5-aminophenanthroline)europium(III),osmium(II)bis(3-(trifluoromethyl)-5-(4-tert-butylpyridyl)-1,2,4-triazolato)diphenylmethylphosphine,osmium(II)bis(3-(trifluoromethyl)-5-(2-pyridyl)-1,2,4-triazole)dimethylphenylphosphine,osmium(II)bis(3-(trifluoromethyl)-5-(4-tert-butylpyridyl)-1,2,4-triazolato)dimethylphenylphosphine,osmium(II)bis(3-(trifluoromethyl)-5-(2-pyridyl)pyrazolato)dimethylphenylphosphine,tris[4,4′-di-tert-butyl(2,2′)-bipyridine]ruthenium(III), osmium(II)bis(2-(9,9-dibutylfluorenyl)-1-isoquinoline(acetylacetonate).

The light emitting layer comprises preferably a compound of the formula

which are described in WO 2005/019373 A2, wherein the symbols have thefollowing meanings:M is a metal atom selected from the group consisting of Co, Rh, Ir, Nb,Pd, Pt, Fe, Ru, Os, Cr, Mo, W, Mn, Tc, Re, Cu, Ag and Au in anyoxidation state possible for the respective metal atom;Carbene is a carbene ligand which may be uncharged or monoanionic andmonodentate, bidentate or tridentate, with the carbene ligand also beingable to be a biscarbene or triscarbene ligand;L is a monoanionic or dianionic ligand, which may be monodentate orbidentate;K is an uncharged monodentate or bidentate ligand selected from thegroup consisting of phosphines; phosphonates and derivatives thereof,arsenates and derivatives thereof; phosphites; CO; pyridines; nitrilesand conjugated dienes which form a π complex with M¹;1 is the number of carbene ligands, where n1 is at least 1 and when n1>1the carbene ligands in the complex of the formula I can be identical ordifferent;m1 is the number of ligands L, where m1 can be 0 or 1 and when m1>1 theligands L can be identical or different;o is the number of ligands K, where o can be 0 or 1 and when o>1 theligands K can be identical or different;where the sum n1+m1+o is dependent on the oxidation state andcoordination number of the metal atom and on the denticity of theligands carbene, L and K and also on the charge on the ligands, carbeneand L, with the proviso that n1 is at least 1.

Carbene complexes which are suitable triplet emitters are described, forexample, in WO 2006/056418 A2, WO 2005/113704, WO 2007/115970, WO2007/115981 and WO 2008/000727, WO2009050281, WO2009050290, WO2011051404and WO2011073149.

More preferred are metal-carbene complexes of the general formula

which are described in U.S. patent applications No. 61/286,046,61/323,885 and European patent application 10187176.2(PCT/EP2010/069541), where M, n1, Y, A², A³, A⁴, A⁵, R⁵¹, R⁵², R⁵³, R⁵⁴,R⁵⁵, R⁵⁶, R⁵⁷, R⁵⁸, R⁵⁹, K, L, m1 and o are each defined as follows:M is Ir, or Pt,n1 is an integer selected from 1, 2 and 3,Y is NR⁵¹, O, S or C(R²⁵)₂,A², A³, A⁴, and A⁵ are each independently N or C, where 2 A=nitrogenatoms and at least one carbon atom is present between two nitrogen atomsin the ring,R⁵¹ is a linear or branched alkyl radical optionally interrupted by atleast one heteroatom, optionally bearing at least one functional groupand having 1 to 20 carbon atoms, cycloalkyl radical optionallyinterrupted by at least one heteroatom, optionally bearing at least onefunctional group and having 3 to 20 carbon atoms, substituted orunsubstituted aryl radical optionally interrupted by at least oneheteroatom, optionally bearing at least one functional group and having6 to 30 carbon atoms, substituted or unsubstituted heteroaryl radicaloptionally interrupted by at least one heteroatom, optionally bearing atleast one functional group and having a total of 5 to 18 carbon atomsand/or heteroatoms,R⁵², R⁵³, R⁵⁴ and R⁵⁵ are each, if A², A³, A⁴ and/or A⁵ is N, a freeelectron pair, or, if A², A³,A⁴ and/or A⁵ is C, each independently hydrogen, linear or branched alkylradical optionally interrupted by at least one heteroatom, optionallybearing at least one functional group and having 1 to 20 carbon atoms,cycloalkyl radical optionally interrupted by at least one heteroatom,optionally bearing at least one functional group and having 3 to 20carbon atoms, substituted or unsubstituted aryl radical optionallyinterrupted by at least one heteroatom, optionally bearing at least onefunctional group and having 6 to 30 carbon atoms, substituted orunsubstituted heteroaryl radical optionally interrupted by at least oneheteroatom, optionally bearing at least one functional group and havinga total of 5 to 18 carbon atoms and/or heteroatoms, group with donor oracceptor action, orR⁵³ and R⁵⁴ together with A³ and A⁴ form an optionally substituted,unsaturated ring optionally interrupted by at least one furtherheteroatom and having a total of 5 to 18 carbon atoms and/orheteroatoms,R⁵⁶, R⁵⁷, R⁵⁸ and R⁵⁹ are each independently hydrogen, linear orbranched alkyl radical optionally interrupted by at least oneheteroatom, optionally bearing at least one functional group and having1 to 20 carbon atoms, cycloalkyl radical optionally interrupted by atleast one heteroatom, optionally bearing at least one functional groupand having 3 to 20 carbon atoms, cycloheteroalkyl radical optionallyinterrupted by at least one heteroatom, optionally bearing at least onefunctional group and having 3 to 20 carbon atoms, substituted orunsubstituted aryl radical optionally interrupted by at least oneheteroatom, optionally bearing at least one functional group and having6 to 30 carbon atoms, substituted or unsubstituted heteroaryl radicaloptionally interrupted by at least one heteroatom, optionally bearing atleast one functional group and having a total of 5 to 18 carbon atomsand/or heteroatoms, group with donor or acceptor action, orR⁵⁶ and R⁵⁷, R⁵⁷ and R⁵⁸ or R⁵⁸ and R⁵⁹, together with the carbon atomsto which they are bonded, form a saturated, unsaturated or aromatic,optionally substituted ring optionally interrupted by at least oneheteroatom and having a total of 5 to 18 carbon atoms and/orheteroatoms, and/orif A⁵ is C, R⁵⁵ and R⁵⁶ together form a saturated or unsaturated, linearor branched bridge optionally comprising heteroatoms, an aromatic unit,heteroaromatic unit and/or functional groups and having a total of 1 to30 carbon atoms and/or heteroatoms, to which is optionally fused asubstituted or unsubstituted, five- to eight-membered ring comprisingcarbon atoms and/or heteroatoms,R²⁵ is independently a linear or branched alkyl radical optionallyinterrupted by at least one heteroatom, optionally bearing at least onefunctional group and having 1 to 20 carbon atoms, cycloalkyl radicaloptionally interrupted by at least one heteroatom, optionally bearing atleast one functional group and having 3 to 20 carbon atoms, substitutedor unsubstituted aryl radical optionally interrupted by at least oneheteroatom, optionally bearing at least one functional group and having6 to 30 carbon atoms, substituted or unsubstituted heteroaryl radicaloptionally interrupted by at least one heteroatom, optionally bearing atleast one functional group and having a total of 5 to 18 carbon atomsand/or heteroatoms,K is an uncharged mono- or bidentate ligand,L is a mono- or dianionic ligand, preferably monoanionic ligand, whichmay be mono- or bidentate,m1 is 0, 1 or 2, where, when m1 is 2, the K ligands may be the same ordifferent,

-   -   o is 0, 1 or 2, where, when o is 2, the L ligands may be the        same or different.

The compound of formula IX is preferably a compound of the formula:

The homoleptic metal-carbene complexes may be present in the form offacial or meridional isomers, preference being given to the facialisomers.

In the case of the heteroleptic metal-carbene complexes, four differentisomers may be present, preference being given to the pseudo-facialisomers.

The light-emitting layer may comprise further components in addition tothe emitter material. For example, a fluorescent dye may be present inthe light-emitting layer in order to alter the emission color of theemitter material. In addition—in a preferred embodiment—a matrixmaterial can be used. This matrix material may be a polymer, for examplepoly(N-vinylcarbazole) or polysilane. The matrix material may, however,be a small molecule, for example 4,4′-N,N′-dicarbazolebiphenyl (CDP=CBP)or tertiary aromatic amines, for example TCTA. In a preferred embodimentof the present invention, at least one compound of the formula I is usedas matrix material.

In a preferred embodiment, the light-emitting layer is formed from 2 to40% by weight, preferably 5 to 35% by weight, of at least one of theaforementioned emitter materials and 60 to 98% by weight, preferably 75to 95% by weight, of at least one of the aforementioned matrixmaterials—in one embodiment at least one compound of the formula I—wherethe sum total of the emitter material and of the matrix material adds upto 100% by weight.

In particularly preferred embodiment, the light-emitting layer comprisesa compound of formula I, such as, for example,

and two carbene complexes, preferably of formula

In said embodiment, the light-emitting layer is formed from 2 to 40% byweight, preferably 5 to 35% by weight, of

and 60 to 98% by weight, preferably 65 to 95% by weight, of a compoundof the formula I and

where the sum total of the carben complexes and of the compound offormula I adds up to 100% by weight.

Suitable metal complexes for use together with the compounds of theformula I as matrix material and/or hole/exciton blocker material and/orelectron/exciton blocker material and/or hole injection material and/orelectron injection material and/or hole conductor material and/orelectron conductor material, preferably as matrix material and/orhole/exciton blocker material, in OLEDs are thus, for example, alsocarbene complexes as described in WO 2005/019373 A2, WO 2006/056418 A2,WO 2005/113704, WO 2007/115970, WO 2007/115981 and WO 2008/000727.Explicit reference is made here to the disclosure of the WO applicationscited, and these disclosures shall be considered to be incorporated intothe content of the present application.

If the blocking layer for holes/excitons (4) does not comprise anycompounds of the formula I, the OLED has—if a blocking layer for holesis present—hole blocker materials typically used in OLEDs, such as2,6-bis(N-carbazolyl)pyridine (mCPy),2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (bathocuproin, (BCP)),bis(2-methyl-8-quinolinato)-4-phenylphenylato)aluminum(III) (BAlq),phenothiazine S,S-dioxide derivates and1,3,5-tris(N-phenyl-2-benzylimidazolyl)benzene) (TPBl), TPBl also beingsuitable as electron-conducting material. Further suitable hole blockersand/or electron conductor materials are2,2′,2″-(1,3,5-benzenetriyl)tris(1-phenyl-1-H-benzimidazole),2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole,8-hydroxyquinolinolatolithium,4-(naphthalen-1-yl)-3,5-diphenyl-4H-1,2,4-triazole,1,3-bis[2-(2,2′-bipyridin-6-yl)-1,3,4-oxadiazo-5-yl]benzene,4,7-diphenyl-1,10-phenanthroline,3-(4-biphenylyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole,6,6′-bis[5-(biphenyl-4-yl)-1,3,4-oxadiazo-2-yl]-2,2′-bipyridyl,2-phenyl-9,10-di(naphthalene-2-yl)anthracene,2,7-bis[2-(2,2′-bipyridin-6-yl)-1,3,4-oxadiazo-5-yl]-9,9-dimethylfluorene,1,3-bis[2-(4-tert-butylphenyl)-1,3,4-oxadiazo-5-yl]benzene,2-(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline,tris(2,4,6-trimethyl-3-(pyridin-3-yl)phenyl)borane,2,9-bis(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline,1-methyl-2-(4-(naphthalene-2-yl)phenyl)-1H-imidazo[4,5-f][1,10]phenanthroline.In a further embodiment, it is possible to use compounds which comprisearomatic or heteroaromatic rings joined via groups comprising carbonylgroups, as disclosed in WO2006/100298, disilyl compounds selected fromthe group consisting of disilylcarbazoles, disilylbenzofurans,disilylbenzothiophenes, disilylbenzophospholes, disilylbenzothiopheneS-oxides and disilylbenzothiophene S,S-dioxides, as specified, forexample, in PCT applications PCT/EP2008/058207 and PCT/EP2008/058106,which were yet to be published at the priority date of the presentapplication, and disilyl compounds as disclosed in WO2008/034758, as ablocking layer for holes/excitons (4) or as matrix materials in thelight-emitting layer (3).

Suitable electron conductor materials for the layer (5) of the inventiveOLEDs comprise metals chelated to oxinoid compounds, such as2,2′,2″-(1,3,5-phenylene)tris[1-phenyl-1H-benzimidazole] (TPBl),tris(8-quinolinolato)aluminum (Alq₃), compounds based on phenanthroline,such as 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (DDPA=BCP) or4,7-diphenyl-1,10-phenanthroline (DPA), and azole compounds such as2-(4-biphenylyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole (PBD) and3-(4-biphenylyl)-4-phenyl-5-(4-t-butylphenyl)-1,2,4-triazole (TAZ),8-hydroxyquinolinolatolithium (Liq), 4,7-diphenyl-1,10-phenanthroline(BPhen), bis(2-methyl-8-quinolinolato)-4-(phenylphenolato)aluminum(BAlq), 1,3-bis[2-(2,2′-bipyridin-6-yl)-1,3,4-oxadiazo-5-yl]benzene(Bpy-OXD),6,6′-bis[5-(biphenyl-4-yl)-1,3,4-oxadiazo-2-yl]-2,2′-bipyridyl(BP-OXD-Bpy), 4-(naphthalen-1-yl)-3,5-diphenyl-4H-1,2,4-triazole (NTAZ),2,9-bis(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (NBphen),2,7-bis[2-(2,2′-bipyridin-6-yl)-1,3,4-oxadiazo-5-yl]-9,9-dimethylfluorene(Bby-FOXD), 1,3-bis[2-(4-tert-butylphenyl)-1,3,4-oxadiazo-5-yl]benzene(OXD-7), tris(2,4,6-trimethyl-3-(pyridin-3-yl)phenyl)borane (3TPYMB),1-methyl-2-(4-(naphthalen-2-yl)phenyl)-1H-imidazo[4,5-f][1,10]phenanthroline(2-NPIP), 2-phenyl-9,10-di(naphthalen-2-yl)anthracene (PADN),2-(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (HNBphen). Thelayer (5) may serve both to facilitate electron transport and as abuffer layer or barrier layer in order to prevent quenching of theexciton at the interfaces of the layers of the OLED. The layer (5)preferably improves the mobility of the electrons and reduces quenchingof the exciton. In a preferred embodiment, TPBl is used as the electronconductor material. In another preferred embodiment, BCP is used as theelectron conductor material. In principle, it is possible that theelectron conductor layer comprises at least one compound of the formulaI as electron conductor material.

Among the materials mentioned above as hole conductor materials andelectron conductor materials, some may fulfil several functions. Forexample, some of the electron-conducting materials are simultaneouslyhole-blocking materials when they have a low-lying HOMO. These can beused, for example, in the blocking layer for holes/excitons (4).However, it is likewise possible that the function as a hole/excitonblocker is also adopted by the layer (5), such that the layer (4) can bedispensed with.

The charge transport layers can also be electronically doped in order toimprove the transport properties of the materials used, in order firstlyto make the layer thicknesses more generous (avoidance of pinholes/shortcircuits) and in order secondly to minimize the operating voltage of thedevice. For example, the hole conductor materials can be doped withelectron acceptors; for example, phthalocyanines or arylamines such asTPD or TDTA can be doped with tetrafluorotetracyanquinodimethane(F4-TCNQ) or with MoO₃ or WO₃. The electron conductor materials can bedoped, for example, with alkali metals, for example Alq₃ with lithium.In addition, electron conductors can be doped with salts such as Cs₂CO₃,or 8-hydroxyquinolatolithium (Liq). Electronic doping is known to thoseskilled in the art and is disclosed, for example, in W. Gao, A. Kahn, J.Appl. Phys., Vol. 94, No. 1, 1 Jul. 2003 (p-doped organic layers); A. G.Werner, F. Li, K. Harada, M. Pfeiffer, T. Fritz, K. Leo. Appl. Phys.Lett., Vol. 82, No. 25, 23 Jun. 2003 and Pfeiffer et al., OrganicElectronics 2003, 4, 89-103. For example, the hole conductor layer may,in addition to a carbene complex, e.g. Ir(dpbic)₃, be doped with MoO₃ orWO₃. For example, the electron conductor layer may comprise BCP dopedwith Cs₂CO₃.

The cathode (6) is an electrode which serves to introduce electrons ornegative charge carriers. Suitable materials for the cathode areselected from the group consisting of alkali metals of group Ia, forexample Li, Cs, alkaline earth metals of group IIa, for example calcium,barium or magnesium, metals of group IIb of the periodic table of theelements (old IUPAC version), comprising the lanthanides and actinides,for example samarium. In addition, it is also possible to use metalssuch as aluminum or indium, and combinations of all metals mentioned. Inaddition, alkali metal, especially lithium-comprising organometalliccompounds, or alkali metal fluorides, such as, for example, LiF, CsF, orKF can be applied between the organic layer and the cathode in order toreduce the operating voltage.

The OLED according to the present invention may additionally comprisefurther layers which are known to those skilled in the art. For example,a layer which facilitates the transport of the positive charge and/ormatches the band gaps of the layers to one another may be appliedbetween the layer (2) and the light-emitting layer (3). Alternatively,this further layer may serve as a protective layer. In an analogousmanner, additional layers may be present between the light-emittinglayer (3) and the layer (4) in order to facilitate the transport ofnegative charge and/or to match the band gaps between the layers to oneanother. Alternatively, this layer may serve as a protective layer.

In a preferred embodiment, the inventive OLED, in addition to layers (1)to (6), comprises at least one of the following layers mentioned below:

-   -   a hole injection layer between the anode (1) and the        hole-transporting layer (2) having a thickness of 2 to 100 nm,        preferably 5 to 50 nm;    -   a blocking layer for electrons between the hole-transporting        layer (2) and the light-emitting layer (3);    -   an electron injection layer between the electron-transporting        layer (5) and the cathode (6).

Materials for a hole injection layer may be selected from copperphthalocyanine,4,4′,4″-tris(N-3-methylphenyl-N-phenylamino)triphenylamine (m-MTDATA),4,4′,4″-tris(N-(2-naphthyl)-N-phenylamino)triphenylamine (2T-NATA),4,4′,4″-tris(N-(1-naphthyl)-N-phenylamino)triphenylamine (1T-NATA),4,4′,4″-tris(N,N-diphenylamino)triphenylamine (NATA), titanium oxidephthalocyanine, 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane(F4-TCNQ), pyrazino[2,3-f][1,10]phenanthroline-2,3-dicarbonitrile(PPDN), N,N,N′,N′-tetrakis(4-methoxyphenyl)benzidine (MeO-TPD),2,7-bis[N,N-bis(4-methoxyphenyl)amino]-9,9-spirobifluorene(MeO-Spiro-TPD),2,2′-bis[N,N-bis(4-methoxyphenyl)amino]-9,9-spirobifluorene(2,2′-MeO-Spiro-TPD),N,N′-diphenyl-N,N′-di-[4-(N,N-ditolylamino)phenyl]benzidine (NTNPB),N,N′-diphenyl-N,N′-di-[4-(N,N-diphenylamino)phenyl]benzidine (NPNPB),N,N′-di(naphthalen-2-yl)-N,N′-diphenylbenzene-1,4-diamine (α-NPP). Inprinciple, it is possible that the hole injection layer comprises atleast one compound of the formula I as hole injection material. Inaddition, polymeric hole-injection materials can be used such aspoly(N-vinylcarbazole) (PVK), polythiophenes, polypyrrole, polyaniline,self-doping polymers, such as, for example, sulfonatedpoly(thiophene-3-[2[(2-methoxyethoxy)ethoxy]-2,5-diyl) (Plexcore® OCConducting Inks commercially available from Plextronics), and copolymerssuch as poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) alsocalled PEDOT/PSS.

As a material for the electron injection layer, LiF, for example, can beselected. In principle, it is possible that the electron injection layercomprises at least one compound of the formula I as electron injectionmaterial.

The person skilled in the art is aware (for example on the basis ofelectrochemical studies) of how suitable materials have to be selected.Suitable materials for the individual layers are known to those skilledin the art and are disclosed, for example, in WO 00/70655.

In addition, it is possible that some of the layers used in theinventive OLED have been surface-treated in order to increase theefficiency of charge carrier transport. The selection of the materialsfor each of the layers mentioned is preferably determined by obtainingan OLED with a high efficiency and lifetime.

The inventive OLED can be produced by methods known to those skilled inthe art. In general, the inventive OLED is produced by successive vapordeposition of the individual layers onto a suitable substrate. Suitablesubstrates are, for example, glass, inorganic semiconductors or polymerfilms. For vapor deposition, it is possible to use customary techniques,such as thermal evaporation, chemical vapor deposition (CVD), physicalvapor deposition (PVD) and others. In an alternative process, theorganic layers of the OLED can be applied from solutions or dispersionsin suitable solvents, employing coating techniques known to thoseskilled in the art.

In general, the different layers have the following thicknesses: anode(1) 50 to 500 nm, preferably 100 to 200 nm; hole-conducting layer (2) 5to 100 nm, preferably 20 to 80 nm, light-emitting layer (3) 1 to 100 nm,preferably 10 to 80 nm, blocking layer for holes/excitons (4) 2 to 100nm, preferably 5 to 50 nm, electron-conducting layer (5) 5 to 100 nm,preferably 20 to 80 nm, cathode (6) 20 to 1000 nm, preferably 30 to 500nm. The relative position of the recombination zone of holes andelectrons in the inventive OLED in relation to the cathode and hence theemission spectrum of the OLED can be influenced, among other factors, bythe relative thickness of each layer. This means that the thickness ofthe electron transport layer should preferably be selected such that theposition of the recombination zone is matched to the optical resonatorproperty of the diode and hence to the emission wavelength of theemitter. The ratio of the layer thicknesses of the individual layers inthe OLED depends on the materials used. The layer thicknesses of anyadditional layers used are known to those skilled in the art. It ispossible that the electron-conducting layer and/or the hole-conductinglayer have greater thicknesses than the layer thicknesses specified whenthey are electrically doped.

Use of the compounds of the formula I in at least one layer of the OLED,preferably in the light-emitting layer (preferably as a matrix material)and/or in the blocking layer for holes/excitons makes it possible toobtain OLEDs with high efficiency and with low use and operatingvoltage. Frequently, the OLEDs obtained by the use of the compounds ofthe formula I additionally have high lifetimes. The efficiency of theOLEDs can additionally be improved by optimizing the other layers of theOLEDs. For example, high-efficiency cathodes such as Ca or Ba, ifappropriate in combination with an intermediate layer of LiF, can beused. Shaped substrates and novel hole-transporting materials whichbring about a reduction in the operating voltage or an increase in thequantum efficiency are likewise usable in the inventive OLEDs. Moreover,additional layers may be present in the OLEDs in order to adjust theenergy level of the different layers and to facilitateelectroluminescence.

The OLEDs may further comprise at least one second light-emitting layer.The overall emission of the OLEDs may be composed of the emission of theat least two light-emitting layers and may also comprise white light.

The OLEDs can be used in all apparatus in which electroluminescence isuseful. Suitable devices are preferably selected from stationary andmobile visual display units and illumination units. Stationary visualdisplay units are, for example, visual display units of computers,televisions, visual display units in printers, kitchen appliances andadvertising panels, illuminations and information panels. Mobile visualdisplay units are, for example, visual display units in cellphones,tablet PCs, laptops, digital cameras, MP3 players, vehicles anddestination displays on buses and trains. Further devices in which theinventive OLEDs can be used are, for example, keyboards; items ofclothing; furniture; wallpaper.

In addition, the present invention relates to a device selected from thegroup consisting of stationary visual display units such as visualdisplay units of computers, televisions, visual display units inprinters, kitchen appliances and advertising panels, illuminations,information panels, and mobile visual display units such as visualdisplay units in cellphones, tablet PCs, laptops, digital cameras, MP3players, vehicles and destination displays on buses and trains;illumination units; keyboards; items of clothing; furniture; wallpaper,comprising at least one inventive organic light-emitting diode or atleast one inventive light-emitting layer.

The following examples are included for illustrative purposes only anddo not limit the scope of the claims. Unless otherwise stated, all partsand percentages are by weight.

EXAMPLES Example 1

a) 16.4 ml (27.9 mmol) t-butyl-lithium in pentane are added to asolution of 5.00 g (12.1 mmol) 9-(8-bromodibenzofuran-2-yl)carbazole,the synthesis of which is described in WO2010079051, in 30 ml water freetetrahydrofurane (THF) at −78° C. under argon. After 15 minutes 2.93 g(15.8 mmol) 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane areslowly added. The reaction mixture is stirred for 3 h at −78° C. underargon poured into water and the water phase is extracted with diethylether. The organic phase is dried with magnesium sulfate and the solventis removed. Crystallization from ether results in 2.57 g of compound 1(yield: 46%).

¹H NMR (400 MHz, CDCl₃): δ 8.50 (s, 1H), 8.18-8.23 (m, 3H), 8.05 (dd,J=8.3 Hz, J=1.3 Hz, 1H), 7.80-7.82 (m, 1H), 7.64-7.70 (m, 2H), 7.43-7.49(m, 4H), 7.28-7.37 (m, 2H), 1.43 (s, 12H).

b) 11.3 g (50.0 mmol) 3-(2-Aminophenyl)-1H-benzimidazol-2-one are addedto 50 g polyphosphoric acid at 180° C. The reaction mixture is stirredat 220° C. for 3 h under nitrogen and poured into water. The product isfiltered off and washed with water and methanol. 50 ml 30% sodiumhydroxide solution are added to a suspension of the product in 200 mlTHF. The mixture is stirred for 30 minutes and the organic phase isseparated, dried with magnesium sulfate and the solvent is distilledoff. 9.26 g of compound 2 are obtained (yield: 89%).

¹H NMR (400 MHz, DMSO-d6): δ 7.88 (d, J=7.7 Hz, 2H), 7.39 (d, J=8.0 Hz,2H), 7.12-7.16 (m, 2H), 6.97-7.01 (m, 2H).

The synthesis of 5H-benzimidazo[1,2-a]benzimidazole and3-(2-aminophenyl)-1H-benzimidazol-2-one is described in Bull. Soc. Chem.Belg. 96 (1987) 787.

c) 5.00 g (13.4 mmol) 2-bromo-8-iodo-dibenzofuran, the synthesis ofwhich is described in EP1885818, 8.74 g (26.8 mmol) caesium carbonate,255 mg (1.34 mmol) copper(I) iodide and 309 mg (2.68 mmol) L-proline areadded to 2.78 g (13.4 mmol) 5H-benzimidazo[1,2-a]benzimidazole in 75 mldimethylformamide under nitrogen. The reaction mixture is heated for 19h at 150° C. and filtered on Hyflo Super Cel® medium, Fluka 56678, CAS[91053-39-3] with THF. The organic phase is washed with water. Thesolvent is distilled off. Column chromatography on silica gel withtoluene/ethyl acetate 19/1 results in compound 3 (yield: 2.29 g(37.7%)).

¹H NMR (400 MHz, THF-d8): δ 8.66 (s, 1H), 8.41 (s, 1H), 8-01-8-16 (m,3H), 7.89 (d, J=8.8 Hz, 1H), 7.63-7.75 (m, 4H), 7.25-7.49 (m, 4H).

d) 1.98 g (3.41 mmol) of compound 1 and 4.02 g (16.6 mmol) potassiumphosphate tribasic monohydrate, 15 ml dioxane, 60 ml toluene and 12 mlwater are added to 1.50 g (3.32 mmol) of the compound 3. The mixture isdegassed with argon. 81 mg (0.199 mmol)2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl (SPhos) and 74 mg (0.033mmol) palladium(II) acetate are added. The reaction mixture is degassedwith argon and is stirred for 4.5 h at 100° C. under argon. 40 ml of a1% sodium cyanide solution are added and the reaction mixture isrefluxed for 1 h. Dichloromethane is added, the organic phase is washedwith water and dried with magnesium sulfate. Column chromatography onsilica gel with toluene and then toluene/ethyl acetate 9/1 results incompound A-1 (yield: 1.42 g (61%)).

¹H NMR (400 MHz, THF-d8): δ 8.71 (s, 1H), 8.54-8.58 (m, 2H), 8.41 (s,1H), 8.20 (d, J=7.8 Hz, 2H), 7.62-8.11 (m, 12H), 7.26-7.31 (m, 10H).

Example 2

The synthesis of 4H-imidazo[1,2-a]benzimidazole is described in ARKIVOC2002 (v) 48-61.

a) 8.02 g (51.0 mmol) 4H-imidazo[1,2-a]benzimidazole, 15.9 g (56.1 mmol)1-bromo-3-iodo-benzene, 33.2 g (102 mmol) caesium carbonate, 1.94 g(10.2 mol) copper (I) iodide and 2.35 g (20.4 mol) L-proline in 200 mldimethyl sulfoxide (DMSO) are stirred for 24 h at 100° C. The solids arefiltered off and washed with dichloromethane. The organic phase iswashed with water and dried with magnesium sulfate. The solvent isdistilled off. Column chromatography with toluene and then toluene/ethylacetate (20/1) results in a product mixture (3.89 g (24%) isomer A and4.46 g (28%) isomer B). Separation of the two isomers is achieved bygradient column chromatography with toluene/ethyl acetate (toluene 100%,toluene/ethyl acetate 95/5, toluene/ethyl acetate 90/10 and ethylacetate100%).

¹H NMR (400 MHz, THF-d⁸): δ 8.54-8.56 (m, 1H), 8.33 (dd, J=7.8 Hz, J=1.4Hz, 1H), 7.80 (d, J=2.8 Hz, 1H), 7.76 (d, J=2.8 Hz, 1H), 7.79 (d, J=8.6Hz, 2H), 7.39-7.46 (m, 2H), 7.20-7.29 (m, 1H), 7.12-7.16 (m, 1H).

¹H NMR (400 MHz, THF-d⁸): δ 8.23 (s, 1H), 7.95-7.97 (m, 1H), 7.70-7.74(m, 2H), 7.56 (s, 1H), 7.45-7.53 (m, 2H), 7.24-7.33 (m, 2H), 7.17 (s,1H).

b) The synthesis of compound C-1 is carried out in analogy to thesynthesis of compound A-1.

¹H NMR (400 MHz, THF-d8): 8.63 (s, 1H), 8.52 (s, 1H), 8.42 (s, 1H),8.32-8.35 (m, 1H), 8.20-8.22 (m, 2H), 7.59-8.02 (m, 10H), 7.40-7.47 (m,4H), 7.09-7.20 (m, 4H).

c) The synthesis of the product of Example 2c) is carried out in analogyto the synthesis of compound A-1.

¹H NMR (400 MHz, THF-d8): δ=8.51 (d, J=1.7 Hz, 1H), 8.41 (d, J=2.1 Hz,1H), 8.37-8.39 (m, 1H), 8.21 (s, 1H), 8.19 (s, 1H), 7.98 (dd, J=8.6 Hz,J=1.9 Hz, 1H), 7.91-7.94 (m, 2H), 7.65-7.82 (m, 6H), 7.57 (d, J=1.5 Hz,1H), 7.37-7.44 (m, 4H), 7.24-7.34 (m, 4H), 7.12 (d, J=1.5 Hz, 1H).

Application Example 1 Mixed-Matrix

The ITO substrate used as the anode is first cleaned with commercialdetergents for LCD production (Deconex® 20NS, and 25ORGAN-ACID®neutralizing agent) and then in an acetone/isopropanol mixture in anultrasound bath. To eliminate any possible organic residues, thesubstrate is exposed to a continuous ozone flow in an ozone oven forfurther 25 minutes. This treatment also improves the hole injectionproperties of the ITO. Then Plexcore® OC AJ20-1000 (commerciallyavailable from Plextronics Inc.) is spin-coated and dried to form a holeinjection layer (˜40 nm).

Thereafter, the organic materials specified below are applied by vapordeposition to the clean substrate at a rate of approx. 0.5-5 nm/min atabout 10⁻⁷-10⁻⁹ mbar. As a hole transport and exciton blocker,

(Ir(dpbic)₃) (for preparation, see Ir complex (7) in the applicationWO2005/019373) is applied to the substrate with a thickness of 20 nm,wherein the first 10 nm are doped with MoO_(x) (˜10%) to improve theconductivity.

Subsequently, a mixture of 30% by weight of emitter compound,

8% by weight of compound Ir(dpbic)₃ and 62% by weight of compound

is applied by vapor deposition in a thickness of 30 nm.

Subsequently, the material BAlq

is applied by vapour deposition with a thickness of 5 nm as blocker.

Next, a Cs₂CO₃ doped BCP

layer is applied as electron transport layer by vapor deposition in athickness of 20 nm and finally a 100 nm-thick Al electrode completes thedevice.

All fabricated parts are sealed with a glass lid and a getter in aninert nitrogen atmosphere.

Application Example 2 Single-Matrix

Production and construction of an OLED as in the application example 1,except the emission-layer consists only of 30% by weight of compound

and 70% by weight of compound

i.e. does not comprise compound Ir(dpbic)₃.

To characterize the OLED, electroluminescence spectra are recorded atvarious currents and voltages. In addition, the current-voltagecharacteristic is measured in combination with the light output emitted.The light output can be converted to photometric parameters bycalibration with a photometer. To determine the lifetime, the OLED isoperated at a constant current density and the decrease in the lightoutput is recorded. The lifetime is defined as that time which lapsesuntil the luminance decreases to half of the initial luminance.

Voltage @ EQE¹⁾ @ Lifetime @ EML 300 nits [V] 300 nits [%] 4000 nits [h]CIE Appl. Mixed- 3.8 V 14.7% 125 h 0.17/0.33 Ex. 1 Matrix Appl. Single-3.6 V 14.2%  65 h 0.17/0.34 Ex. 2 Matrix ¹⁾External quantum efficiency(EQE) is # of generated photons escaped from a substance or a device/#of electrons flowing through it.

Example 3

3.30 g (10 mmol) 1,3-diiodobenzene, 13.0 g (40.0 mmol) caesiumcarbonate, 1.90 g (1.00 mmol) copper(I) iodide and 2.30 g (20.0 mmol)L-proline are added to 4.56 g (22.0 mmol) mmol)5H-benzimidazo[1,2-a]benzimidazole in 100 ml dimethylsulfoxide (DMSO)under nitrogen. The reaction mixture is stirred for 5 h at 100° C. Thereaction mixture is poured into water and the product is filtered off.The product is two times crystallized form toluene. Yield 1.6 g (48%).MS (APCI(pos): m/z=489 (M⁺¹).

¹H NMR (400 MHz, THF-d8): δ 8.79 (s, 1H), 8.22 (d, J=8.4 Hz, 2H),8.15-8.18 (m, 2H), 8.00-8.06 (m, 4H), 7.88 (t, J=8.1 Hz, 1H) 7.71 (d,J=7.9 Hz, 2H), 7.41-7.49 (m, 4H), 7.25-7.34 (m, 4H).

Example 4

a) 7.78 g (25 mmol) 1-bromo-3-iodo-benzene, 16.3 g (50.0 mmol) caesiumcarbonate, 1.24 g (6.50 mmol) copper(I) iodide and 1.50 g (13.0 mmol)L-proline are added to 5.18 g (25.0 mmol) mmol)5H-benzimidazo[1,2-a]benzimidazole in 100 ml dimethylsulfoxide (DMSO)under nitrogen. The reaction mixture is stirred for 18 h at 100° C. Thereaction mixture is poured into water. The organic phase is extractedwith dichloromethane. The organic phase is dried with magnesium sulfate.The solvent is distilled of. Column chromatography on silica gel withtoluene gives the product. Yield 8.35 g (92%).

¹H NMR (400 MHz, CDCl₃): δ 8.25 (s, 1H), 7.90-8.05 (m, 3H), 7.95-8.05(m, 3H), 7.71 (d, J=7.9 Hz, 1H), 7.65 (d, J=7.9 Hz, 1H). 7.50-7.65 (m,2H), 7.26-7.45 (m, 4H).

b) 1.09 g (3.00 mmol) of the product of example 4a). 690 mg (2.70 mmol)4,4,5,5-tetramethyl-2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1,3,2-dioxaborolane,5.86 g (1.80 mmol) potassium carbonate in 20 ml DMF are degassed withargon. 1,1′-Bis(diphenylphosphino) ferrocen)dichlorpalladium(II) areadded and the reaction mixture is degassed with argon. The reactionmixture is stirred for 18 h at 80° C. The product is filtered off andwashed with dimethylformamide (DMF), water and methanol. Yield 370 mg(44%).

¹H NMR (400 MHz, CDCl₃): δ 8.43 (s, 2H), 7.95-8.10 (m, 6H) 7.70-7.90 (m,6H), 7.63 (d, J=7.6 Hz, 2H), 7.20-7.45 (m, 8H).

Example 5

a) 5.78 g (16.0 mmol) of the product of example 4a). 12.16 g (47.8 mmol)4,4,5,5-tetramethyl-2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1,3,2-dioxaborolane,12.5 g (0.128 mol) potassium acetate in 50 ml DMF are degassed withargon. 1,1′-Bis(diphenylphosphino) ferrocen)dichlorpalladium(II) areadded and the reaction mixture is degassed with argon. The reactionmixture is stirred for 22 h at 60° C. and poured into a saturatedsolution of sodium chloride in water. The water phase is extracted withtetrahydrofuran (THF), the organic phase is dried with magnesium sulfateand the solvent is distilled off. The product is crystallized fromdiethyl ether and cyclohexane. Yield 3.62 g (59%).

¹H NMR (400 MHz, THF-d8): δ 8.26 (s, 1H), 8.09-8.10 (m, 1H), 8.07-8.09(m, 2H), 7.86 (s, J=7.6 Hz, 1H), 7.60-7.67 (m, 3H), 7.28-7.42 (m, 4H),1.39 (s, 12H).

b) 2.72 g (6.01 mmol)5-(8-bromodibenzofuran-2-yl)benzimidazolo[1,2-a]benzimidazole and 6.92 g(3.01 mmol) potassium phosphate tribasic monohydrate, 27 ml dioxane, 100ml toluene and 21 ml water are added to 3.20 g (7.82 mmol) of5-[3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]benzimidazolo[1,2-a]benzimidazole. The mixture is degassed with argon.148 mg (0.361 mmol) 2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl(SPhos) and 135 mg (0.060 mmol) palladium(II) acetate are added. Thereaction mixture is degassed with argon and is stirred for 22 h at 100°C. under argon. 110 ml of a 1% sodium cyanide solution are added and thereaction mixture is refluxed for 1 h. Dichloromethane is added, theorganic phase is washed with water and dried with magnesium sulfate. Theproduct is decocted with methanol (yield: 1.62 g (41%)).

¹H NMR (400 MHz, THF-d8): δ 8.69 (d, J=1.1 Hz, 1H), 8.57 (d, J=1.6 Hz,1H), 8.42 (s, 1H), 8.05-8.08 (m, 1H), 7.89-7.99 (m, 6H), 7.80-7.85 (m,2H), 7.76-7.75 (m, 4H), 7.57-7.61 (m, 2H), 7.18-7.37 (m, 8H).

Example 6

a) 20.0 g (78.8 mmol) 1,3-dibromo-5-fluoro-benzene, 16.3 g (78.8 mmol)6H-benzimidazolo[1,2-a]benzimidazole and 43.5 g (0.315 mmol) potassiumcarbonate in 200 ml DMF are stirred for 17 h at 170° C. The reactionmixture is filtered hot and the precipitate from the mother liquor isfiltered after cooling. The product is washed with water and ethanol anddecocted with diethyl ether and ethanol. Yield 21.2 g (61%).

¹H NMR (400 MHz, THF-d8): δ 8.21-8.26 (m, 4H), 7.98-7.8.00 (m, 1H),7.68-7.73 (m, 2H), 7.31-7.49 (m, 4H).

b) 2.00 g (4.53 mmol)5-(3,5-dibromophenyl)benzimidazolo[1,2-a]benzimidazole and 4.15 g (3.00mmol) potassium carbonate, 27 ml dioxane, 100 ml toluene and 21 ml waterare added to 3.20 g (7.82 mmol) of2-dibenzofuran-2-yl-4,4,5,5-tetramethyl-1,3,2-dioxaborolane. The mixtureis degassed with argon. 37 mg (0.090 mmol)2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl (SPhos) and 10 mg(0.0045 mmol) palladium(II) acetate are added. The reaction mixture isdegassed with argon and is stirred under argon for 19 h at 120° C. 110ml of a 1% sodium cyanide solution are added and the reaction mixture isrefluxed for 1 h. The solvent is distilled off. 30 ml toluene are added,the product is filtered off, washed with water and cyclohexane andcrystallized from methyl butyl ketone (MEK). Yield 1.84 g (66%).

¹H NMR (400 MHz, THF-d8): δ 8.21-8.26 (m, 4H), 7.98-7.8.00 (m, 1H),7.68-7.73 (m, 2H), 7.31-7.49 (m, 4H).

Example 7

The product of Example 7 is prepared in analogy to the proceduredescribed in example 6.

¹H NMR (400 MHz, DMSO-d6): δ 8.59 (d, J=1.5 Hz, 2H), 8.46-8.47 (m, 1H),8.24-8.33 (m, 6H), 8.13 (d, J=8.0 Hz, 1H), 7.99-8.01 (m, 2H), 7.78 (d,J=8.2 Hz, 2H), 7.37-7.68 (m, 9H), 7.29-7.37 (m, 2H)

Example 8

3.85 g (8.51 mmol)5-(8-bromodibenzofuran-2-yl)benzimidazolo[1,2-a]benzimidazole and 10.3 g(4.26 mmol) potassium phosphate tribasic monohydrate, 20 ml dioxane, 80ml xylene and 16 ml water are added to 2.01 g (4.09 mmol) of4,4,5,5-tetramethyl-2-[3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]-1,3,2-dioxaborolane.The mixture is degassed with argon. 210 mg (0.511 mmol)2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl (SPhos) and 191 mg(0.085 mmol) palladium(II) acetate are added. The reaction mixture isdegassed with argon and is stirred for 22 h at 100° C. under argon. 110ml of a 1% sodium cyanide solution are added and the reaction mixture isrefluxed for 1 h. Dichloromethane is added. The organic phase is washedwith water and dried with magnesium sulfate. The product is decoctedwith diethylether. Yield 1.31 g (39%).

¹H NMR (400 MHz, DMF-d7): δ 8.90 (d, J=1.7 Hz, 2H), 8.86 (d, J=2.2 Hz,2H), 8.37 (s, 1H), 8.26-8.31 (m, 4H), 8.14-8.21 (m, 4H), 8.08-8.11 (m,2H), 7.94-7.96 (m, 2H), 7.89-7.93 (m, 2H), 7.76-7.78 (m, 2H), 7.66-7.71(m, 3H), 7.32-7.49 (m, 8H)

Example 9

a) 2,6-Diiodo-dibenzofuran is prepared according to Example 13 ofWO2011/111423 and purified by crystallisation from cyclohexane.

b) The product of Example 9 is prepared in analogy to the proceduredescribed in Example 5.

Example 10

4.20 g (10 mmol) 2,8-diiododibenzofuran, 13.0 g (40.0 mmol) caesiumcarbonate, 1.90 g (1.00 mmol) copper(I) iodide and 2.30 g (20.0 mmol)L-proline are added to 4.56 g (22.0 mmol) mmol)5H-benzimidazo[1,2-a]benzimidazole in 100 ml dimethylsulfoxide (DMSO)under nitrogen. The reaction mixture is stirred for 24 h at 100° C.,filtered and washed with dichloromethane. The organic phase is driedwith magnesium sulfate and the solvent is distilled off. The product iscrystallized form ether. Yield 4.7 g (81%)

¹H NMR (400 MHz, THF-d8): δ 8.73 (d, J=1.2 Hz, 2H), 8.14 (d, J=2.3 Hz,J=8.8 Hz, 2H), 7.96-8.02 (m, 4H), 7.92 (d, J=8.8 Hz, 2H), 7.70-7.73 (m,2H), 7.62 (d, J=7.1 Hz, 2H), 7.25-7.40 (m, 8H).

Example 11

a) 2-Bromo-dibenzofuran is prepared according E. Hand, J. Org. Chem. 62(1997) 1348 and purified by crystallization from tert-butyl methyl ether(TBME).

b) 47.27 g (0.199 mol) of 2-Bromo-benzofuran are dissolved in 440 ml dryTHF and cooled to −78° C. under argon. Within 1 h a solution of lithiumdiisopropylamide (LDA; prepared from 81.2 ml (0.219 mol) n-butyllithium(2.7M in heptane) and 20.18 g (0.199 mol) Diisopropylamin in 250 ml ofdry THF) is added, keeping the temperature below −73° C. The resultingyellow solution is stirred for 2 h at −78° C. A solution of 50.6 g(0.199 mol) iodine dissolved in 150 ml dry THF is then added within 50minutes, keeping the temperature below −73° C. The resulting brownsolution is warmed to room temperature, poured into 500 ml of buffersolution pH=7 and neutralized to pH=7 with 2N HCl. The organic solventis evaporated and the aqueous phase extracted three times withethylacetate. The combined organic phases are washed three times withwater, dried with magnesium sulfate, filtered and the solvent isevaporated. Two crystallizations from cyclohexane/TBME=1:1 result in35.0 g of 2-bromo-4-iodo-dibenzofuran (yield: 45.6%).

¹H NMR (400 MHz, CDCl₃): δ 7.99 (d, J=1.8 Hz, 1H), 7.95 (d, J=1.8 Hz,1H), 7.85 (d, J=8 Hz, 1H), 7.63 (d, J=8 Hz, 1H), 7.51 (t, J=8 Hz, 1H),7.37 (t, J=8 Hz, 1H).

Example 12

a) 4-Bromo-dibenzofuran is prepared according to Example 1 ofUS2011/0006670 and purified by crystallisation from methanol.

b) 6-Bromo-2-iodo-dibenzofuran is prepared according to Example 1 ofUS2011/0006670 and purified by crystallisation from 2-propanol.

c) 1.00 g (2.68 mmol) 6-bromo-2-iodo-dibenzofuran, 1.75 g (5.36 mmol)caesium carbonate, 130 mg (0.67 mmol) copper(I) iodide and 150 mg (1.34mmol) L-proline are added to 670 mg (3.22 mmol)5H-benzimidazo[1,2-a]benzimidazole in 20 ml DMSO under nitrogen. Thereaction mixture is stirred for 18 h at 100° C. and filtered. THF andtoluene are added to the organic phase and the organic phase is washedwith water. The organic phase is dried with magnesium sulfate and thesolvent is distilled off. The product can be used without furtherpurification in step d) (yield=650 mg (78%)).

¹H NMR (400 MHz, CDCl₃): δ 8.66 (d, J=2.2 Hz, 1H), 8.13-8.19 (m, 2H),7.96-8.07 (m, 3H), 7.66-7.78 (m, 3H), 7.25-7.45 (m, 5H).

d) The product of Example 12 is prepared in analogy to the proceduredescribed in Example 5. MS (APCI(pos), m/z): 615.5 (M⁺¹). ¹H NMR (400MHz, THF-d8): 8.68 (d, J=2.1 Hz, 1H), 8.34 (t, J=1.8 Hz, 1H), 8.21 (d,J=7.7 Hz, 3H), 7.85-7.15 (m, 7H), 7.65-7.77 (m, 5H), 7.47-7.58 (m, 3H),7.28-7.44 (m, 6H).

Example 13

The synthesis of9-[3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]carbazole isdescribed in Chem. Mater. 20 (2008) 1691-1693. The product of Example 21is prepared in analogy to the procedure described in Example 5.

Example 14

2-Iodo-dibenzofuran is prepared according to A. Kryska, Journal ofChemical Research, Miniprint 10 (1999) 2501 and purified bycrystallisation from methanol.

Example 15

a) 2,4-Diiodo-dibenzofuran is prepared in analogy to the proceduredescribed in Example 11, starting from 2-iodo-dibenzofuran (Example 14)and purified by crystallisation from 2-propanol (yield: 80%).

¹H NMR (400 MHz, CDCl₃): δ 8.17 (s, 1H), 8.07 (s, 1H), 7.84 (d, J=7.6Hz, 1H), 7.63 (d, J=7.6 Hz, 1H), 7.51 (t, J=7.6 Hz, 1H), 7.37 (t, J=7.6Hz, 1H).

b) The product of Example 15 is prepared in analogy to the proceduredescribed in Example 10.

Example 16

a) 7.00 g (24.7 mmol) 1-bromo-4-iodo-benzene, 10.5 g (32.2 mmol) caesiumcarbonate, 2.36 g (12.4 mmol) copper(I) iodide and 2.85 g (24.7 mmol)L-proline are added to 5.13 g (24.7 mmol) mmol)5H-benzimidazo[1,2-a]benzimidazole in 80 ml DMSO under nitrogen. Thereaction mixture is stirred for 15 h at 100° C. and 4 h at 150° C.,filtered on Hyflo with dichloromethane. The organic phase is washed withwater. The organic phase is dried with magnesium sulfate. The product isdecocted with diethylether and methyl ethyl ketone (MEK). Yield: 2.90 g(77%).

¹H NMR (400 MHz, DMF-d7): δ 7.93-8.10 (m, 4H), 7.78-7.92 (m, 2H),7.72-7.79 (m, 1H), 7.49-7.71 (m, 1H), 7.31-7.49 (m 4H).

b) The product of Example 16b) is prepared in analogy to the proceduredescribed in Example 4b).

¹H NMR (400 MHz, DMF-d7): δ=8.19-8.33 (m, 10H), 7.83-7.87 (m, 2H),7.73-7.77 (m, 2H), 7.35-7.54 (m, 4H). One signal is covered by DMF

MS (APCI(pos), m/z): 565 (M⁺¹).

Example 17

The product of Example 17 is prepared in analogy to the proceduredescribed in Example 4b).

Example 18

The product of Example 18 is prepared in analogy to the proceduredescribed in Example 5b). MS (APCI(pos), m/z): 615 (M⁺¹).

Example 19

2 g (4.04 mmol) 3,6-diiodo-9-phenyl-carbazole, 5.26 g (16.2 mmol)caesium carbonate, 190 mg (0.101 mmol) copper(I) iodide and 233 mg (2.02mmol) L-proline are added to 1.84 g (8.89 mmol)5H-benzimidazo[1,2-a]benzimidazole in 40 ml DMSO under nitrogen. Thereaction mixture is stirred for 10 h at 150° C., filtered on Hyflo SuperCel® medium (Fluka 56678, CAS [91053-39-3]) and washed withdichloromethane. The organic phase is dried with magnesium sulfate andthe solvent is distilled off. Gradient column chromatography withcyclohexane/toluene (cyclohexane 100%, cyclohexane/toluene 10/1,cyclo-hexane/toluene 4/1) result in the product (yield: 70 mg (3%)). MS(APCI(pos), m/z): 654 (M⁺¹).

¹H NMR (400 MHz, THF-d8): δ=8.81 (d, J=1.9 Hz, 2H), 7.99-7.05 (m, 6H),7.70-7.83 (m, 11H), 7.22-7.41 (m, 8H).

In addition to Cpd. A-12 the following compounds have been detected byHPLC-MS:

(MS (APCI(pos), m/z): 449 (M⁺¹)).

(MS (APCI(pos), m/z): 575 (M⁺¹)).

Example 20

a) The product of Example 20a) is prepared in analogy to the proceduredescribed in Example 1c). Reference is made to J. Heterocyclic Compounds(1989) 168 and J. Org. Chem 42 (1977) 542 with respect to the synthesisof 4H-[1,2,4]triazolo[1,5-a]benzimidazole and the starting materialsused for its synthesis. MS (MALDI-MS (m/z): 403 (M⁺¹).

b) The product of Example 20b) is prepared in analogy to the proceduredescribed in Example 13).

Example 21

a) 5 g (31.6 mmol) 4H-[1,2,4]triazolo[1,5-a]benzimidazole, 20.6 g (63.2mmol) caesium carbonate, 1.5 g (7.9 mmol) copper(I) iodide, and 910 mg(7.9 mmol) L-proline are added to 17.8 g (8 mL) (63.2 mmol)1-bromo-3-iodobenzene in 60 mL DMSO under nitrogen. The reaction mixtureis stirred for 15 h at 85° C. The reaction mixture is filtered throughsilica gel with dichloromethane. The organic phase is washed with water,NaCl solution, and dried with sodium sulfate. The product is decoctedwith diethylether (yield: 8.0 g (80%)). ¹H NMR (400 MHz, CD₂Cl₂): δ 8.02(s, 1H), 7.98 (s, 1H), 7.90-7.88 (m, 1H), 7.71-7.68 (m, 1H), 7.60-7.58(d, 1H), 7.52-7.48 (t, 1H), 7.46-7.40 (m, 2H). ¹³C NMR (500 MHz,CD₂Cl₂): δ 155.05 (d, 1C), 153.47 (s, 1C), 136.82 (s, 1C), 134.23 (s,1C), 131.63 (d, 1C), 130.78 (d, 1C), 126.69 (d, 1C), 124.95 (s, 1C),124.87 (d, 1C), 123.50 (s, 1C), 123.26 (d, 1C), 122.45 (d, 1C), 112.15(d, 1C), 111.66 (d, 1C).

b) 1.25 g (4 mmol)4-(3-bromophenyl)-[1,2,4]triazolo[1,5-a]benzimidazole, 2.4 g (5.2 mmol)9-[8-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)dibenzofuran-2-yl]carbazole,and 4.3 g (20 mmol) potassium phosphate in 40 mL toluene are added to 90mg (0.03 mmol) palladium(II) acetate, 100 mg (0.24 mmol)2-dicyclohexylphosphino-2,6-dimethoxybiphenyl (SPhos) in dioxane/water40 mL/10 mL under argon. The reaction mixture is stirred for 15 h at 85°C. and filtered through celite with dichloromethane. The organic phaseis washed with water, NaCl solution, and dried with sodium sulfate(yield: 1.75 g (77%)).

¹H NMR (400 MHz, CD₂Cl₂): δ 8.41 (d, 1H), 8.37 (d, 1H), 8.34 (d, 2H),8.25 (t, 1H), 8.17 (s, 1H), 8.06-8.04 (m, 3H), 7.93-7.86 (m, 4H), 7.84(d, 1H), 7.82 (d, 1H), 7.59-7.54 (m, 6H), 7.47-7.43 (m, 2H). ¹³C NMR(500 MHz, CD₂Cl₂): δ 157.22 (s, 1C), 155.97 (s, 1C), 155.07 (d, 1C),153.80 (s, 1C), 143.30 (s, 1C), 141.80 (s, 2C), 136.12 (s, 1C), 135.79(s, 1C), 134.68 (s, 1C), 133.14 (s, 1C), 130.81 (d, 1C), 127.78 (d, 1C),127.31 (d, 1C), 126.79 (d, 1C), 126.36 (d, 2C), 125.87 (s, 1C), 124.91(s, 1C), 124.89 (s, 1C), 124.76 (d, 1C), 123.51 (d, 2C), 122.92 (d, 1C),122.88 (d, 10), 120.61 (d, 2C), 120.31 (d, 1C), 120.26 (d, 2C), 122.65(d, 1C), 120.03 (d, 1C), 113.40 (d, 1C), 112.66 (d, 10), 112.21 (d, 1C),111.58 (d, 1C), 110.02 (d, 2C).

Example 22

160 mg (0.48 mmol) 1,3-diiodobenzene and 170 mg (1.06 mmol)4H-[1,2,4]triazolo[1,5-a]benzimidazole in 10 mL DMSO are stirred underargon for 15 minutes. 625 mg (1.9 mmol) caesium carbonate, 120 mg (1.06mmol) L-proline, and 90 mg (0.48 mmol) copper(I) iodide are added. Thereaction mixture is stirred for 15 h at 100° C. and filtered throughcelite with dichloromethane. The organic phase is washed with water,NaCl solution, and dried with sodium sulfate. The product iscrystallized from isopropanol (yield: 130 mg (69%)). ¹H NMR (400 MHz,CD₂Cl₂): δ 8.35 (s, 1H), 8.06 (s, 2H), 7.94-7.84 (m, 7H), 7.50-7.42 (m,4H). ¹³C NMR (500 MHz, CD₂Cl₂): δ 155.12 (d, 2C), 153.59 (s, 2C), 137.10(s, 2C), 134.27 (s, 2C), 131.07 (d, 1C), 125.09 (s, 2C), 125.06, (d,2C), 123.39 (d, 2C), 121.80 (d, 2C), 118.36 (d, 1C), 112.51 (d, 2C),111.73 (d, 2C).

Example 23

1 g (2.4 mmol) 2,8-diiodedibenzofuran and 840 mg (5.3 mmol)4H-[1,2,4]triazolo[1,5-a]benzimidazole in 10 mL DMSO are stirred underargon for 15 minutes. 3.1 g mg (9.6 mmol) caesium carbonate, 550 mg (4.8mmol) L-proline, and 460 mg (2.4 mmol) copper(I) iodide are added. Thebrown reaction mixture is stirred for 15 h at 100° C. Water is added tothe reaction mixture and filtered and washed with methanol. The productis crystallized from toluene (yield: 330 mg (28%)). ¹H NMR (400 MHz,CD₂Cl₂): δ 8.38 (s, 1H), 8.05 (s, 2H), 7.92-7.85 (m, 8H), 7.42-7.13 (dd,2H)

Example 24

9-(9H-Carbazol-3-yl)-9H-carbazole is prepared according to a literatureprocedure (J. Org. Chem, 2008, 73, 1809)

a) The product of Example 24a) is prepared according to the procedure ofExample 10. Purification: FC (SiO₂, cyclohexane/CH₂Cl₂ 4:1. Yield: 85%.

¹H NMR (400 MHz, CD₂Cl₂): δ 8.34 (s, 1H), 8.18 (m, 5H), 7.87 (d, 1H),7.77 (d, 1H), 7.67 (d, 1H), 7.59 (m, 3H), 7.51-7.39 (m, 6H), 7.31 (m,3H).

b) Pd(dppf)*CH₂Cl₂ (8 mg, 0.01 mmol) is added to a degassed (Ar) mixtureof 5-[3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]benzimidazolo[1,2-a]benzimidazole (133 mg, 0.33 mmol), the product ofExample 24a) (144 mg, 0.25 mmol) in dioxane (5 mL) and NaOH (3 M, 0.25mL). The reaction mixture is heated for 8 h at 80° C. and filtered overCelite and FC (SiO₂, CH₂Cl₂) gives the product (yield: 50 mg, 26%).

¹H NMR (400 MHz, CD₂Cl₂): δ 8.33 (2×s, 2+1H), 8.18 (m, 4H), 7.88 (m,5H), 7.81-7.73 (m, 4H), 7.69-7.62 (m, 3H), 7.56 (d, 1H), 7.49 (d, 2H),7.42-7.27 (m, 11H).

Application Example 3

The preparation of the ITO substrate as well as the latercharacterization of the complete diode is equivalent to ApplicationExample 1, except that the composition of the following layers differs:

As a hole transport and exciton blocker, Ir(dpbic)₃, is applied to thesubstrate with a thickness of 20 nm, wherein the first 10 nm are dopedwith MoO₃ (˜10%) to improve the conductivity. Subsequently, a mixture of30% by weight of emitter compound,

15% by weight of compound Ir(dpbic)₃ and 55% by weight of compound

is applied by vapor deposition in a thickness of 30 nm.

Subsequently, compound A-10 is applied by vapour deposition with athickness of 5 nm as hole blocker. Subsequently a mixture of 50% byweight of material

and 50% by weight of material

is evaporated as electron transporting layer with a thickness of 20 nm.Finally ˜2 nm KF are deposited as electron injection layer and a 100 nmthick Al electrode completes the device.

Comparative Application Example 1

The production and construction of the OLED is done as in ApplicationExample 3, except for the following: The doping concentration of MoO₃ inIr(dpbic)₃ in the hole transport layer is 5% by weight. The emissivelayer consists of 30% by weight of compound

15% by weight of compound Ir(dpbic)₃ and 55% by weight of compound

The hole blocking layer consists of compound Ref-1 and the electrontransporting layer is 25 nm thick.

Host Voltage @ EQE @ Lifetime @ material 300 nits [V] 300 nits [%] 4000nits* Appl. Ex. 3 A-10 4.02 14.0% 100 Comp. Appl. Ex. 1 Ref-1 4.00 10.8%20 *The measured lifetime of Application Example 3 is set to 100 and thelifetime of Comparative Application Example 1 is specified in relationto those of Application Example 3.

Application Example 4

The production and construction of the OLED is done as in ApplicationExample 3, except for the following: The hole transporting layer withMoO₃ and Ir(dpbic)₃ is 15 nm and the undoped electron blocker,Ir(dpbic)₃, is only 5 nm thick. The emissive layer consists of 30% byweight of compound

10% by weight of compound Ir(dpbic)₃ and 60% by weight of compound

the thickness is 40 nm. The hole blocking layer consists of materialB-5.

Comparative Application Example 2

The production and construction of the OLED is done as in ApplicationExample 3, except for the following: The emissive layer consists of 30%by weight of compound

10% by weight of compound Ir(dpbic)₃ and 60% by weight of compound

the thickness is 40 nm. The hole blocking layer consists of compoundRef-2.

Host Voltage @ Lifetime @ material 300 nits [V] 4000 nits* Appl. Ex. 4B-5 4.55 100 Comp. Appl. Ex. 2 Ref-2 4.34 70 *The measured lifetime ofApplication Example 4 is set to 100 and the lifetime of ComparativeApplication Example 2 is specified in relation to those of ApplicationExample 4.

Application Example 5

The production and construction of the OLED is done as in ApplicationExample 1, except for the following: The emissive layer consists of 30%by weight of compound

10% by weight of compound Ir(dpbic)₃ and 60% by weight of compound

the thickness is 30 nm. The electron transporting layer is 25 nm thick.

Comparative Application Example 3

The production and construction of the OLED is done as in ApplicationExample 1, except for the following: The emissive layer consists of 30%by weight of compound

10% by weight of compound Ir(dpbic)₃ and 60% by weight of compound

the thickness is 30 nm. The electron transporting layer is 25 nm thick.

Host Voltage @ EQE @ material 300 nits [V] 300 nits [%] Appl. Ex. 5 A-203.43 11.3 Comp. Appl. Ex. 3 Ref-3 3.81 13.6 * The measured lifetime ofApplication Example 5 is set to 100 and the lifetime of ComparativeApplication Example 3 is specified in relation to those of ApplicationExample 5.

Application Example 6

The production and construction of the OLED is done as in ApplicationExample 3, except for the following: The emissive layer consists of 30%by weight of compound

10% by weight of compound Ir(dpbic)₃ and 60% by weight of compound

the thickness is 40 nm. The hole blocking layer consists of materialA-3.

Host Voltage @ EQE @ material 300 nits [V] 300 nits[%] CIE Appl. Ex. 6A-20 4.56 12.8 0.18/0.36

The invention claimed is:
 1. A compound of formula (I) shown below

wherein X⁶ is —N═ and X⁷ is —NR¹—, or X⁷ is ═N— and X⁶ is —NR¹—, R¹ is a group of formula -A¹-(A²)_(p)-(A³)_(q)-(A⁴)_(r)-R⁶, p is 0, or 1, q is 0, or 1, r is 0, or 1, A¹, A², A³ and A⁴ are independently of each other a C₆-C₂₄arylene group, which can optionally be substituted by G, or a C₂-C₃₀heteroarylene group, which can optionally be substituted by G; wherein the groups A¹, A², A³ and A⁴ may be interrupted by one, or more groups —(SiR⁷R⁸)—; R², R³, R⁴ and R⁵ are independently of each other H, a C₁-C₂₅alkyl group, which can optionally be substituted by E and or interrupted by D; a C₆-C₂₄aryl group, which can optionally be substituted by G, or a C₂-C₃₀heteroaryl group, which can optionally be substituted by G; R⁶ is a group —(SiR²⁰R²¹R²²), a C₆-C₂₄aryl group, which can optionally be substituted by G, or a C₂-C₃₀heteroaryl group, which can optionally be substituted by G; R⁷ and R⁸ are independently of each other a C₁-C₂₅alkyl group, or a C₆-C₂₄aryl group, which can optionally be substituted by G; X¹ is N, or CR⁹, X² is N, or CR¹⁰, R⁹ and R¹⁰ are independently of each other H, a C₁-C₂₅alkyl group, which can optionally be substituted by E and or interrupted by D; a C₆-C₂₄aryl group, which can optionally be substituted by G, or a C₂-C₃₀heteroaryl group, which can optionally be substituted by G, wherein R⁹ and R¹⁰ together do not form a ring; R²⁰, R²¹ and R²² are independently of each other a C₁-C₂₅alkyl group, or a C₆-C₂₄aryl group, which can optionally be substituted by G; D is —CO—, —COO—, —S—, —SO—, —SO₂—, —O—, —NR⁶⁵—, —SiR⁷⁰R⁷¹—, —POR⁷²—, —CR⁶³═CR⁶⁴—, or —C≡C—, E is —OR⁶⁹, —SR⁶⁹, —NR⁶⁵R⁶⁶, —COR⁶⁸, —COOR⁶⁷, —CONR⁶⁵R⁶⁶, —CN, or halogen, G is E, or a C₁-C₁₈alkyl group, a C₆-C₂₄aryl group, a C₆-C₂₄aryl group, which is substituted by F, C₁-C₁₈alkyl which is interrupted by O, a C₂-C₃₀heteroaryl group, or a C₂-C₃₀heteroaryl group, which is substituted by F, C₁-C₁₈alkyl which is interrupted by O; R⁶³ and R⁶⁴ are independently of each other C₆-C₁₈aryl; C₆-C₁₈aryl which is substituted by C₁-C₁₈alkoxy; C₁-C₁₈alkyl; or C₁-C₁₈alkyl which is interrupted by —O—; R⁶⁵ and R⁶⁶ are independently of each other a C₆-C₁₈aryl group; a C₆-C₁₈aryl which is substituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy; a C₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which is interrupted by —O—; or R⁶⁵ and R⁶⁶ together form a five or six membered ring, R⁶⁷ is a C₆-C₁₈aryl group; a C₆-C₁₈aryl group, which is substituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy; a C₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which is interrupted by —O—, R⁶⁸ is H; a C₆-C₁₈aryl group; a C₆-C₁₈aryl group, which is substituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy; a C₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which is interrupted by —O—, R⁶⁹ is a C₆-C₁₈aryl; a C₆-C₁₈aryl, which is substituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy; a C₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which is interrupted by —O—, R⁷⁰ and R⁷¹ are independently of each other a C₁-C₁₈alkyl group, a C₆-C₁₈aryl group, or a C₆-C₁₈aryl group, which is substituted by C₁-C₁₈alkyl, and R⁷² is a C₁-C₁₈alkyl group, a C₆-C₁₈aryl group, or a C₆-C₁₈aryl group, which is substituted by C₁-C₁₈alkyl, wherein when X⁷ is ═N— and X⁶ is —NR¹—, R⁶ is a group of formula

or a group SiR²⁰R²¹R²²); wherein R¹¹, R¹², R¹³ and R¹⁴ are independently of each other H, a C₁-C₂₅alkyl group, which can optionally be substituted by E and or interrupted by D; a C₆-C₂₄aryl group, which can optionally be substituted by G, or a C₂-C₃₀heteroaryl group, which can optionally be substituted by G, R¹⁶ is a C₆-C₁₈aryl group; or a C₆-C₁₈aryl group, which is substituted by one, or more C₁-C₁₈alkyl groups, R⁴³ may be the same, or different in each occurrence and is F, C₁-C₁₈alkyl, C₁-C₁₈alkyl which is substituted by E and/or interrupted by D, C₆-C₂₄aryl, C₆-C₂₄aryl which is substituted by G, C₂-C₂₀heteroaryl, or C₂-C₂₀heteroaryl which is substituted by G, and m3 is 0, or an integer of 1 to 4, m4 is 0, or an integer of 1 to
 3. 2. The compound according to claim 1, which is a compound of formula

wherein X¹, X², R¹, R², R³, R⁴ and R⁵ are as defined in claim
 1. 3. The compound according to claim 1, which is a compound of formula

wherein X⁶ is —N═ and X⁷ is —NR¹—, or X⁷ is ═N— and X⁶ is —NR¹— and R¹, R², R³, R⁴, R⁵, R⁹ and R¹⁰ are as defined in claim
 1. 4. The compound according to claim 3, which is a compound of formula

wherein R¹ is a group of formula -A¹-(A²)_(p)-(A³)_(q)-(A⁴)_(r)-R⁶, p is 0, or 1, q is 0, or 1, r is 0, or 1, A¹, A², A³ and A⁴ are independently of each other a C₆-C₂₄arylene group, which can optionally be substituted by G, or a C₂-C₃₀heteroarylene group, which can optionally be substituted by G; wherein the groups A¹, A², A³ and A⁴ may be interrupted by one, or more groups —(SiR⁷R⁸)—; R², R³, R⁴ and R⁵ are independently of each other H, a C₁-C₂₅alkyl group, which can optionally be substituted by E and or interrupted by D; a C₆-C₂₄aryl group, which can optionally be substituted by G, or a C₂-C₃₀heteroaryl group, which can optionally be substituted by G; R⁶ is a group —(SiR²⁰R²¹R²²), a C₆-C₂₄aryl group, which can optionally be substituted by G, or a C₂-C₃₀heteroaryl group, which can optionally be substituted by G; R⁷ and R⁸ are independently of each other a C₁-C₂₅alkyl group, or a C₆-C₂₄aryl group, which can optionally be substituted by G; R⁹ and R¹⁰ are independently of each other H, a C₁-C₂₅alkyl group, which can optionally be substituted by E and or interrupted by D; a C₆-C₂₄aryl group, which can optionally be substituted by G, or a C₂-C₃₀heteroaryl group, which can optionally be substituted by G, wherein R⁹ and R¹⁰ together do not form a ring; R²⁰, R²¹ and R²² are independently of each other a C₁-C₂₅alkyl group, or a C₆-C₂₄aryl group, which can optionally be substituted by G; D is —CO—, —COO—, —S—, —SO—, —SO₂—, —O—, —NR⁶⁵—, —SiR⁷⁰R⁷¹—, —POR⁷²—, —CR⁶³═CR⁶⁴—, or —C≡C—, E is —OR⁶⁹, —SR⁶⁹, —NR⁶⁵R⁶⁶, COR⁶⁸, —COOR⁶⁷, —CONR⁶⁵R⁶⁶, —CN, or halogen, G is E, or a C₁-C₁₈alkyl group, a C₆-C₂₄aryl group, a C₆-C₂₄aryl group, which is substituted by F, C₁-C₁₈alkyl, C₁-C₁₈alkyl which is interrupted by O, a C₂-C₃₀heteroaryl group, or a C₂-C₃₀heteroaryl group, which is substituted by F, C₁-C₁₈alkyl, C₁-C₁₈alkyl which is interrupted by O; R⁶³ and R⁶⁴ are independently of each other C₆-C₁₈aryl; C₆-C₁₈aryl which is substituted by C₁-C₁₈alkyl, C₁-C₁₈alkoxy; C₁-C₁₈alkyl; or C₁-C₁₈alkyl which is interrupted by —O—; R⁶⁵ and R⁶⁶ are independently of each other a C₆-C₁₈aryl group; a C₆-C₁₈aryl which is substituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy; a C₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which is interrupted by —O—; or R⁶⁵ and R⁶⁶ together form a five or six membered ring, R⁶⁷ is a C₆-C₁₈aryl group; a C₆-C₁₈aryl group, which is substituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy; a C₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which is interrupted by —O—, R⁶⁸ is H; a C₆-C₁₈aryl group; a C₆-C₁₈aryl group, which is substituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy; a C₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which is interrupted by —O—, R⁶⁹ is a C₆-C₁₈aryl; a C₆-C₁₈aryl, which is substituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy; a C₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which is interrupted by —O—, R⁷⁰ and R^(7′) are independently of each other a C₁-C₁₈alkyl group, a C₆-C₁₈aryl group, or a C₆-C₁₈aryl group, which is substituted by C₁-C₁₈alkyl, and R⁷² is a C₁-C₁₈alkyl group, a C₆-C₁₈aryl group, or a C₆-C₁₈aryl group, which is substituted by C₁-C₁₈alkyl.
 5. The compound according to claim 1, wherein R¹ is a group of formula -A¹-(A²)_(p)-(A³)_(q)-(A⁴)_(r)-R⁶, or

wherein A¹, A², A³ and A⁴ are independently of each other a group of formula

wherein m5 is 0, or an integer of 1 to 4, m2 is 0, or an integer 1 to 3, X³ is —O—, —S—, or —NR¹⁵—, R⁷ and R⁸ are a C₁-C₁₈alkyl group, R¹⁵ is a C₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which is interrupted by —O—; a C₆-C₁₈aryl group; a C₆-C₁₈aryl group, which is substituted by one, or more C₁-C₁₈alkyl, or C₁-C₁₈alkoxy groups; a C₂-C₂₀heteroaryl group, or a C₂-C₂₀heteroaryl group, which is substituted by one, or more C₁-C₁₈alkyl groups, R⁴¹ may be the same, or different in each occurrence and is F, C₁-C₁₈alkyl, C₁-C₁₈alkyl which is substituted by E and/or interrupted by D, C₆-C₂₄aryl, C₆-C₂₄aryl which is substituted by G, C₂-C₂₀heteroaryl, or C₂-C₂₀heteroaryl which is substituted by G, and R⁶, p, q r, E, D and G are as defined in claim
 1. 6. The compound according to claim 5, wherein A¹, A², A³ and A⁴ are independently of each other a group of formula

wherein R¹⁵ is a C₆-C₁₈aryl group; or a C₆-C₁₈aryl group, which is substituted by one, or more C₁-C₁₈alkyl groups.
 7. The compound according to claim 1, wherein R⁶ is a group of formula

or a group —(SiR²⁰R²¹R²²), wherein R², R³, R⁴, R⁵, R¹¹, R¹², R¹³ and R¹⁴ are independently of each other H, a C₁-C₂₅alkyl group, which can optionally be substituted by E and or interrupted by D; a C₆-C₂₄aryl group, which can optionally be substituted by G, or a C₂-C₃₀heteroaryl group, which can optionally be substituted by G, R¹⁶ is a C₆-C₁₈aryl group; or a C₆-C₁₈aryl group, which is substituted by one, or more C₁-C₁₈alkyl groups, R²⁰, R²¹ and R²² are independently of each other a C₆-C₁₈aryl group; or a C₆-C₁₈aryl group, which is substituted by one, or more C₁-C₁₈alkyl groups, R⁴³ may be the same, or different in each occurrence and is F, C₁-C₁₈alkyl, C₁-C₁₈alkyl which is substituted by E and/or interrupted by D, C₆-C₂₄aryl, C₆-C₂₄aryl which is substituted by G, C₂-C₂₀heteroaryl, or C₂-C₂₀heteroaryl which is substituted by G, m3 is 0, or an integer of 1 to 4, m4 is 0, or an integer of 1 to 3, and E, D, and G are as defined in claim
 1. 8. The compound according to claim 7, wherein R⁶ is a group of formula

R¹⁶ is a C₆-C₁₈aryl group; or a C₆-C₁₈aryl group, which is substituted by one, or more C₁-C₁₈alkyl groups.
 9. The compound according to claim 1, which is a compound of formula

wherein R¹ is a group of formula -A¹-(A²)p-(A³)q-(A⁴)r-R⁶ or

A¹, A², A³ and A⁴ are independently of each other a group of formula

wherein m5 is 0, or an integer of 1 to 4, m2 is 0, or an integer 1 to 3, X³ is —O—, or —NR¹⁵—, R⁷ and R⁸ are a C₁-C₁₈alkyl group, R¹⁵ is a C₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which is interrupted by —O—; a C₆-C₁₈aryl group; a C₆-C₁₈aryl group, which is substituted by one, or more C₁-C₁₈alkyl, or C₁-C₁₈alkoxy groups; a C₂-C₂₀heteroaryl group, or a C₂-C₂₀heteroaryl group, which is substituted by one, or more C₁-C₁₈alkyl groups, R⁴¹ may be the same, or different in each occurrence and is F, C₁-C₁₈alkyl, C₁-C₁₈alkyl which is substituted by E and/or interrupted by D, C₆-C₂₄aryl, C₆-C₂₄aryl which is substituted by G, C₂-C₂₀heteroaryl, or C₂-C₂₀heteroaryl which is substituted by G, R⁶ is a group of formula

R⁴³ may be the same, or different in each occurrence and is F, C₁-C₁₈alkyl, C₁-C₁₈alkyl which is substituted by E and/or interrupted by D, C₆-C₂₄aryl, C₆-C₂₄aryl which is substituted by G, C₂-C₂₀heteroaryl, or C₂-C₂₀heteroaryl which is substituted by G, m3 is 0, or an integer of 1 to 4; or R¹ is a group of formula -A¹-(A²)_(p)-(A³)_(q)-(A⁴)_(r)-R⁶, wherein A¹, A², A³ and A⁴ are independently of each other a group of formula

R6 is a group of formula,

R², R³, R⁴, R⁵, p, q, r, E, D and G are ad defined in claim 1, and R¹¹, R¹², R¹³, and R¹⁴ are independently of each other H, a C₁-C₂₅alkyl group, which can optionally be substituted by E and or interrupted by D; a C₆-C₂₄aryl group, which can optionally be substituted by G, or a C₂-C₃₀heteroaryl group, which can optionally be substituted by G.
 10. The compound according to claim 1:

Cpd. L¹ ³⁾ R⁶ J-1 

J-2 

J-3 

J-4 

J-5 

J-6 

J-7 

J-8 

J-9 

J-10

J-11

J-12

J-13

J-14

J-15

J-16

J-17

J-18

J-19

J-20

J-21

J-22

J-23

J-24

J-25

J-26

J-27

J-28

J-29

J-30

J-31

J-32

J-33

J-34

J-35

Cpd. L¹ ³⁾ R⁶ K-1 

K-2 

K-3 

K-4 

K-5 

K-6 

K-7 

K-8 

K-9 

K-10

K-11

K-12

K-13

K-14

K-15

K-16

K-17

K-18

K-19

K-20

K-21

K-22

K-23

K-24

K-25

K-26

K-27

K-28

K-29

K-30

K-31

K-32

K-33

K-34

K-35

Cpd. L¹ ⁴⁾ R⁶ L-1 

L-2 

L-3 

L-4 

L-5 

L-6 

L-7 

L-8 

L-9 

L-10

L-11

L-12

L-13

L-14

L-15

L-16

L-17

L-18

L-19

L-20

L-21

L-22

L-23

L-24

L-25

L-26

L-27

L-28

L-29

L-30

L-31

L-32

L-33

L-34

L-35

³) the dotted line indicates the bond to the groups of formula

respectively, and ⁴⁾the dotted line indicates the bond to the group of formula


11. The compound according to claim 1, wherein the group of formula -A¹-(A²)_(p)-(A³)_(q)-(A⁴), is a group of formula

wherein R¹⁵ is a C₆-C₁₈aryl group; or a C₆-C₁₈aryl group, which is substituted by one, or more C₁-C₁₈alkyl groups.
 12. The compound according to claim 11, wherein R⁶ is a group of formula

wherein, R², R³, R⁴, R⁵, R¹¹, R¹², R¹³ and R¹⁴ are independently of each other H, a C₁-C₂₅alkyl group, which can optionally be substituted by E and or interrupted by D; a C₆-C₂₄aryl group, which can optionally be substituted by G, or a C₂-C₃₀heteroaryl group, which can optionally be substituted by G, R¹⁶ is a C₆-C₁₈aryl group; or a C₆-C₁₈aryl group, which is substituted by one, or more C₁-C₁₈alkyl groups, R²⁰, R²¹ and R²² are independently of each other a C₆-C₁₈aryl group; or a C₆-C₁₈aryl group, which is substituted by one, or more C₁-C₁₈alkyl groups, R⁴³ may be the same, or different in each occurrence and is F, C₁-C₁₈alkyl, C₁-C₁₈alkyl which is substituted by E and/or interrupted by D, C₆-C₂₄aryl, C₆-C₂₄aryl which is substituted by G, C₂-C₂₀heteroaryl, or C₂-C₂₀heteroaryl which is substituted by G, m3 is 0, or an integer of 1 to 4, m4 is 0, or an integer of 1 to 3, and D is —CO—, —COO—, —S—, —SO—, —SO₂—, —O—, —NR⁶⁵—, —SiR⁷⁰R⁷¹—, —POR⁷²—, —CR⁶³═CR⁶⁴—, or —C≡C—, E is —OR⁶⁹, SR⁶⁹, —NR⁶⁵R⁶⁶, —COR⁶⁸, —COOR⁶⁷, —CONR⁶⁵R⁶⁶, —CN, or halogen, G is E, or a C₁-C₁₈alkyl group, a C₆-C₂₄aryl group, a C₆-C₂₄aryl group, which is substituted by F, C₁-C₁₈alkyl, C₁-C₁₈alkyl which is interrupted by O, a C₂-C₃₀heteroaryl group, or a C₂-C₃₀heteroaryl group, which is substituted by F, C₁-C₁₈alkyl, C₁-C₁₈alkyl which is interrupted by O; R⁶³ and R⁶⁴ are independently of each other C₆-C₁₈aryl; C₆-C₁₈aryl which is substituted by C₁-C₁₈alkyl, C₁-C₁₈alkoxy; C₁-C₁₈alkyl; or C₁-C₁₈alkyl which is interrupted by —O—; R⁶⁵ and R⁶⁶ are independently of each other a C₆-C₁₈aryl group; a C₆-C₁₈aryl which is substituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy; a C₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which is interrupted by —O—; or R⁶⁵ and R⁶⁶ together form a five or six membered ring, R⁶⁷ is a C₆-C₁₈aryl group; a C₆-C₁₈aryl group, which is substituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy; a C₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which is interrupted by —O—, R⁶⁸ is H; a C₆-C₁₈aryl group; a C₆-C₁₈aryl group, which is substituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy; a C₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which is interrupted by —O—, R⁶⁹ is a C₆-C₁₈aryl; a C₆-C₁₈aryl, which is substituted by C₁-C₁₈alkyl, or C₁-C₁₈alkoxy; a C₁-C₁₈alkyl group; or a C₁-C₁₈alkyl group, which is interrupted by —O—, R⁷⁰ and R⁷¹ are independently of each other a C₁-C₁₈alkyl group, a C₆-C₁₈aryl group, or a C₆-C₁₈aryl group, which is substituted by C₁-C₁₈alkyl, and R⁷² is a C₁-C₁₈alkyl group, a C₆-C₁₈aryl group, or a C₆-C₁₈aryl group, which is substituted by C₁-C₁₈alkyl.
 13. The compound according to claim 1, wherein R², R³, R⁴ and R⁵ are H.
 14. The compound according to claim 1, wherein R⁹ and R¹⁰ are H, or C₆-C₁₄aryl, which may optionally be substituted by one, or more C₁-C₈alkyl groups; or C₂-C₃₀heteroaryl, which may optionally be substituted by one, or more C₁-C₈alkyl groups.
 15. An electronic device comprising a compound according to claim
 1. 16. The electronic device according to claim 15, which is an electroluminescent device.
 17. A hole transport layer, or an emitting layer comprising the compounds of formula (I) according to claim
 1. 18. An apparatus selected from the group consisting of stationary visual display units including visual display units of computers, televisions, visual display units in printers, kitchen appliances and advertising panels, illuminations, information panels, and mobile visual display units including visual display units in cellphones, tablet PCs, laptops, digital cameras, MP3 players, vehicles and destination displays on buses and trains; illumination units; keyboards; items of clothing; furniture; wallpaper, comprising an electronic device, a hole transport layer, or an emitting layer which comprises the compounds of formula (I) according to claim
 1. 19. A method of using the compounds of formula (I) of claim 1 comprising: adding the compounds of formula (I) to electrophotographic photoreceptors, photoelectric converters, organic solar cells (organic photovoltaics), switching elements, organic light emitting field effect transistors (OLEFETs), image sensors, dye lasers and electroluminescent devices, wherein X⁶ is —N═ and X⁷ is —NR¹—, or X⁷ is ═N— and X⁶ is —NR¹—, R¹ is a group of formula -A¹-(A²)_(p)-(A³)_(q)-(A⁴)_(r)-R⁶, p is 0, or 1, q is 0, or 1, r is 0, or 1, A¹, A², A³ and A⁴ are independently of each other a C₆-C₂₄arylene group, which can optionally be substituted by G, or a C₂-C₃₀heteroarylene group, which can optionally be substituted by G; wherein the groups A¹, A², A³ and A⁴ may be interrupted by one, or more groups —(SiR⁷R⁸)—; R², R³, R⁴ and R⁵ are independently of each other H, a C₁-C₂₅alkyl group, which can optionally be substituted by E and or interrupted by D; a C₆-C₂₄aryl group, which can optionally be substituted by G, or a C₂-C₃₀heteroaryl group, which can optionally be substituted by G; R⁶ is H, a group —(SiR²⁰R²¹R²²), a C₆-C₂₄aryl group, which can optionally be substituted by G, or a C₂-C₃₀heteroaryl group, which can optionally be substituted by G; R⁷ and R⁸ are independently of each other a C₁-C₂₅alkyl group, or a C₆-C₂₄aryl group, which can optionally be substituted by G; wherein X¹, X², R⁷, R⁸, R²⁰, R²¹, R²² E, D and G are as defined in claim
 1. 